+ Low level & item dependency
+ Long lasting disable since first level
+ Powerful AoE nuke
+ Helps the whole team with mana
+ When well used, ultimate can be devastating
- Very squishy
- VERY slow movement speed
- Slow attack animation (hard to deny)
- Disable isn't a real stun
- Ultimate is hard to use correctly
- Can only play the Support role
Due to her frailty and slow movement and attack speed, strong spells, and 0 escape skills, Crystal Maiden has to play the support role. She's actually is one of the best at it, with a AoE nuke that slows and deals a good chunk of damage ( Crystal Nova), high-duration semi reliable stun ( Frostbite), an aura that benefits the whole team wherever they are ( Arcane Aura), and a very hard-hitting ultimate that slows ( Freezing Field, unfortunately not very reliable).
A support hero is the one that doesn't benefit as well as others from gold income, and that doesn't have enough survivability/escape to solo a lane. As such, Crystal Maiden should focus on everything that boosts her team instead of herself, and the player should be very selfless. She won't be the one doing triple kills and carrying the game, but she'll be very important in combat and maybe the gamebreaking piece, if you play your cards right.
So, keep in mind that you need to buy stuff like wards, courier, dust and gems, as well as focus your item builds in helping the team, like building a Mekanism or Urn to heal them.
Crystal Maiden should never solo a lane, since she's so slow, bad at last hitting, and has terrible survivability. She's best served when put together with a Hard Carry in the Easy Lane, but can support on the other lanes as well, and can combo for early ganks or even trilane.
While in laning phase, focus on staying near the xp range, but as far from trouble as you can. When near the tower, you can try a Frostbite to initiate a gank, but when you are far, you will probably end up in trouble.
You should also focus on map awareness, keeping Observer Wards up, and protecting the carry. You can even body-block to prevent your carry from dying, even if it costs your death, it may be well worth it for the late game.
Try to Stack 'n' Pull the neutral camps to keep the lane safe for the carry. If you don't know how to do that, we'll get to it. Or, you can scroll down and see "Stack and Pull" chapter. =D
Frostbite is taken first due to its utility in ganks and in saving your teammate, probably a hard carry. Next, you can choose between Crystal Nova or Arcane Aura, but I recommend aura, for this 0.5 extra regen will help all the other lanes. If you do, get a point in Crystal Nova at lvl 3.
First skill to max is Arcane Aura, helping all the team all along the game with huge mana regen. It goes well with the philosophy of support role: decisions that boost your team first.
You should max Frostbite afterwards for the extra lock time. I used to max Crystal Nova for the higher damage output, but since you WILL BE walking with team, you should prioritize the extra disable time.
Lastly, don't grab ultimate too early. I advise for level 10 and 11. It's too situational in the begining of the game, and you don't have enough mana to chain all your spells, with Crystal Nova and Frostbite being better most of the time.
Some people don't max Arcane Aura after grabbing a couple of points in it. Specially after a recent Buff, where CM gets double of the aura regen, this is pretty viable. If you do so, just proceed maxing the other skills.
Optional Build 2
Some people also don't level Arcane Aura. I feel like this one is a bad choice, but if your team has the intention on grabbing lots of mana items, or is really not thaaat dependant on mana, you could go for a more tankier CM by grabbing stats instead of aura. Grab a fast Urn if you go this route, so that you get more tanky and have mana regen. I don't recommend this build, and much prefer previous builds.
Cristal Nova is a AoE nuke that slows both attack and movement speed. It is very strong during team fights because it will cripple multiple enemies at once, slowing and dealing a good amount of damage, but also because it has a HUGE HUGE range. Crystal Nova range is 700 (a little bigger than CM's attack range) and you get 200 extra range from its radius, so it's a 900 range spell. You can safely initiate fights with that without even going into trouble.
Very straigh forward skill, it will keep your enemy on ground. Keep in mind that this doesn't prevent heroes from casting spells, although they cannot flee from it with Blink of Invisibility.
Keeping it on level 1 will make for a more spamable skill that is enough for a kill.
It has a shorter range, so, if needed, cast a Crystal Nova to chase first.
Grab this ASAP because it helps your team in the whole map. If not for this reason, it also grants you enough mana regen so that you don't need to waste coins on it, so it's a win-win skill.
Timing your Freezing Field into a double or triple-kill is really tricky, since it's a channeling spell that WILL be interrupted by stuns. It is NOT like Enigma's ultimate, a initiation skill. Instead, Freezing Field is the last skill to be cast, after the initiation has taken place, and most importantly, the enemies' stun are down.
Other than that, Freezing Field is VERY useful when enemies engage your allies in team fights, because it will slow their attack (protecting your allies), slow their move (preventing them from running away) and increasing your DPS greatly.
I tend to buy Ring of Protection to accelerate Tranquil Boots, although it's an usual choice to buy Gauntlets of Strength too. The ring will give you better survivability against right-click damage, but less against spell harassing, so be aware.
You will usually be sitting back, so you won't get much harm. It's not unusual to use Healing Salve to heal your teammate, since 3 Tangoes are usually good enough for you, if you don't risk yourself too much.
DON'T LEAVE BASE before Animal Courier is bought, if it was not bought, it's your duty to do so. If someone else bought it, buy Observer Wards. If people know their gaming and wards are also bought, buy Sentry Wards to counter-ward the pulling camp (see "Stack and Pull").
Flying Courier is very important, so try to buy it fast. Boots of Speed makes a lot of difference for you, so aim for it before any other item.
As the support, your DUTY is to BUY Observer WardS. You NEED to ward the map, and every once in a while you will have to give up that amazing item you wanted just to buy some more wards.
Tranquil Boots are just awesome for CM, since she will be always back in fights, she'll benefit from the high move speed most of the time, and the regeneration is great for letting you stick with your team after a fight, or when with low life.
Bracer is much needed for the extra life, and can be turned into Drums later.
You can also rush Urn of Shadows instead of bracer, but I recomend at least one bracer afterwards.
These are very important items that every team should have one of each. Since everyone benefits from a single one, you shouldn't build them without checking if noone else in your team already started to do so.
Right after finishing Core items, you should commit into building these for your team, which will help them greatly and give you extra utility in later stages of the game.
Urn of Shadows is very good for you, giving you the extra support skill of healing, the extra Nuke if needed, and granting much needed extra Tankiness, and enough mana that you won't need mana items during the rest of the game.
Mekansm is the kind of item every team needs, and you can safely go for it when noone else is doing so. It can turn the tides of a team fight if used corretly.
Pipe of Insight is situational, but most teams have some kind of AoE nuke that will be countered by a Pipe. Use it right before initiation from your team, or before opposing team's initiation, and it will grant 400 extra life for everyone.
Also, you get to live longer with the added Resistance and Regen, so, all the best.
Drum of Endurance is that item that noone notice, but is there, helping the whole team a lot. Very useful for CM that lacks move speed, and easily built, since it's built from her core Bracer.
When everything is set, your Core is built, wards are up, courier is flying, and your team got Meka, Urn, Pipe, and Drums, it's time to check what your team needs more, and build situational items. If the game is hard and you don't have much to spend, increasing your HP with bracers or Club isn't a bad idea as well, since you need to last at least a bit to be helpful.
Magic Wand - VERY useful item, it's better when facing a harass intense line, but most people consider it core.
Black King Bar is bought when your enemies got too much nuke for you, and has the added benefit of letting you cast Freezing Field in peace. A very good item, for it also increases your HP, but situational in the sense that, against a right-click intense team, you probably will prefer a Ghost Scepter or something else.
Blink Dagger, for Crystal Maiden, isn't all that useful. It is good to blink into the fight AFTER initiation is done, but if you try to initiate, you'll be to pieces before your team ever enter fight.
Eul's Scepter of Divinity is prefered for Crystal Maiden when your team need extra disables, and since CM would take forever to build a Guinsoo, Eul's is the way to go. It can also save your @ss in the process.
Gem of True Sight - When the enemies got too much invis, you should be buying this for your Tank or Carry, and dropping it to them, so that they can invest the gold in other items. Don't walk around with it, tho, since you are fragile.
Dust of Appearance is prefered when you need to carry the counter to invis, since it's cheap, can be used as soon as fight start, and won't drop when you die. Buy these if your team need the slots, or if Gem is under cooldown.
Medallion of Courage looks like a weird item to build, but the armor and mana regen here will help you well, and since you will be preferably back during team fights, you can reduce your team target's armor pretty safely. Prefered when your team relies on right-click damage.
Veil of Discord is built when your team has a lot of AoE spells, such as Akasha, Venom among others.
Ghost Scepter will let you live enough to cast your spells against heavy Right-click damage. It's the perfect 'counter' to a Carry with a BKB.
Bracer - I consider the second Bracer optional, for the moments in which you are on a tight budget and your team needs you to stay alive a little longer on team fights. If you have a little more coins, go for Ogre Club instead.
Ogre Club will move you towards a very good BKB while increasing your HP by 190. Just really good.
These are items that looks fancy and good in theory, but are often too expensive and not as helpful as the previous mentioned items.
Aghanim, although increasing your HP by a good chunk, demands too much investment to finish, and your ultimate is too situational for it to be worthy.
Bloodstone isn't need for the whole mana part, being half a waste.
Guinsoo is really REALLY good, but by the time your 0.68 attacks per second get you the money, you either won without it, or lost due to the lack of it, when you could just have built a Cyclone.
Tarrasque is expensive, but if you have all that gold, MAYBE it's a good idea.
Dagon demands investiment to it, and has to get finished fast, or it loses its strenght, so it's not for you.
As a support, you should ALWAYS ward the map for your team. If you are new to this, I recomend the excelent Ultimate Guide to Warding, but for starters, keep in mind the 2 most important ward positions, which are the Rune spots, which also are the Jungle entrances for the game:
.This is the top rune ward, wich is also entrance to Dire jungle
.This is the bottom rune ward, which is entrance to Radiant jungle and also to Roshan
If you are Radiant, the priority is to place the bottom rune ward. If you are Dire, the top one.
If you are supporting in the easy lane, it would be very nice if you could stack and pull creeps. To help you understanding and learning how to do this, here's a very good video (credits to XV Rogue Gaming, hope you don't mind the link):
This is a very good video about supporting in general, but stacking 'n' pulling is at 04:00, but here is the full video if you want to learn more. (Recomended!)
- Rylai Crestfall, the Crystal Maiden, is one of the oldest heroes in DotA, along with Luna, Sniper and others, but she was called Frost Maiden before (back to when it was Dota 3.6c @ Warcraft 3 - Reign of Chaos)