How to play this build
This is a guide to playing a support/ casting lich
Lich is a great hero who can harass, is great in team fights, and isn't too bad on his own.
As you are a support you will be buying the courier.
You will want the tangos after any ganks or too much harassment (though you should be the one harassing).
The Sage's mask will help to spam frost blast.
The Mask will be upgraded to a ring, which will give armor and mana regen to nearby allies, and will increase your mana.
Headdress is to support your laning partner from taking too much damage, and to give you some regen.
Boots of Speed go without saying, help with chasing, retreating, etc.
Wand will help with mana and hp a bit.
Power Treads will give you a bit more tank, so that you don't instantly get wiped in any teamfights.
Mekansm is really good in teamfights, so make sure to use it only when needed. This is where you're starting to become a really strong support.
Aganhim's scepter is great, giving you even more damage in teamfights.
The Scythe is good in chasing/ teamfights for removing the most damaging hero in a fight.
Refresher Orb because double chain frost = 550*7*2 = A possible 7.7k damage. Bloody hell.
For Skills, spam Frost Blast as much as possible, mana should not be a problem.
Use Ice Armor on the first creep when pushing, as it will slow down all the enemy creeps attacking it. Also use it on you and your laning ally, to increase armor.
Chain Frost should only be used in a team fight.
In a teamfight:
Use Ice Armor on your carry > other supports > others.
Use Frost Blast where the fight breaks out, then use your chain frost. If needed, use your mekansm. Then use the refresher orb. Use another Frost Blast, then give your teammates armor and use the chain frost if the enemy is still alive.