Pick the 3 most relevant

I'm thinking about getting into dota again. I haven't been playing since the greevil update and now I'm looking into starting a new account and try to master 3 heroes. I intend to play ranked matches as soon as I'm able to and I'd like your help.
These are the heroes I think I might like most:

- Ember Spirit;
- Bounty Hunter;
- Nature's Prophet;
- Tusk;
- Doom;
- Slark;

I read that playing mid is the best to climb the ranking ladders but since that's not possible every game it should be better to pick a mid hero and a offlaner at least.

Give me your opinion on which group of these 3 would be best and suit more games.

hmm this past patch I've been seeing a lot of Slark play on the pro scene. NP is still relevant in the pushing game as an offlaner. I wouldn't worry about embe spirit right now as far as ranked since he isn't available in captains mode. Your list is pretty short tho so I would just play all pick games and try to play as those heroes you listed to get comfortable with them all.

Actually Jabo, Ember Spirit was added to Captain's Mode in the recent patch.

Easy: Nature's Prophet, Doom and Slark. NP and Slark are good off-laners and can be also played in different positions - jungle for NP, mid or safe lane for Slark - while Doom is one of the best utility Heroes and his ultimate will always be worth picking him. Slark, particularly, is between the "top 3 most overpowered off-lane Heroes" in the current patch (along with Timbersaw and Bristleback); Nature's Prophet is really good for split pushing if the enemies don't carry TP scrolls and is still one of the most picked off-laners. If you only need mids Doom and Slark are enough, but playing jungle Nature's Prophet should lead to easy - or even easier - victories, too.

Bounty Hunter can also be a choice if you're playing versus people who don't carry invisibility detection, but I have better results with the formers.

Oh snap, thanks xCo2, I didn't know that. I haven't really played Ember too much and haven't played much against him, but good to know

I personally like Ember Spirit, although my winrate (not average game scores!) is disturbingly low :O

Slark and Doom bringer are genuinely strong picks atm.

Ember Spirit, Slark and Doom bringer would therefor by my choices.

Thanks a lot for the input Peppo.
Would Doom be better in lane or woods?
Another thing, I've only seen Nature's Prophet playing woods but from what you wrote I guess he can be viable in lane too?
Once again, thanks for putting the time to help me.

For Doom it really depends on your team: if you have a carry but no mids go mid, if you have no carry go to the safe lane, if you have both a carry and a mid go to jungle. Generically, I'd say mid > safe lane > jungle unless you can play a very good jungle Doom.

For Slark I think off-lane (or dual hard lane) > mid > safe lane since he isn't a very good Hero for the #1 position but, after his level 6, he can go roam and snowball by getting kills.

Nature's Prophet is probably the most common jungler in pubs, and I wouldn't play dual lanes with him. If I were you I'd stick to jungle since you'll very rarely play in a solo lane and you have to manage your Treants efficiently (blocking pulling camps, getting vision, making last-hits easier...) in order to have a good laning stage. Mid NP is also played, but I think many Heroes need the mid lane more than him and, as he's Bottle-independent, it's very easy for the other mid to get all the runes if you don't know how to manage Treants.

I wouldn't reccomend Slark offlane, he's relatively easy to shut down against 2-3 heroes solo, I'd say dual lane in the offlane, but avoid safe lane because there are carries that do better with safe lane farm, while Slark is gank dependent in a sense, as soon as he's level 6, you can really start being a nuisance. He snowballs very hard if he nets those early kills, just don't expect him to outcarry most of the hard carries available., it's about controlling the map with him and pressing your advantage, he can be an absolute nightmare.
Mid he is matchup dependent, there are obvious heroes you do not want him in the midlane against (ie. Storm Spirit, Queen of Pain), generally, he should destroy melee mid heroes. Also, don't rush Skadi, you'll get it if you're performing well anyway, Shadow Blade, drums of endurance, Sange and Yasha combine well, the movement speed, stats, invis, all work wonders for the mid game. Racetrack Slark=better map control, easier pounces.

If you do Attempt doom bringer jungle , YouTube it first, pubs or unfamiliar players in general can be painfully slow in the jungle with him due to his lack of armor, had a guy yesterday still at level 4 at the 8min mark, rushing his late midas, burned through his regen and was running to the fountain a lot.