Dota 2/Rooftrellen the Treant Protector

Treant Protector is a melee strength hero who is usually played as an initiator, a support or a semi-carry. Although his abilities seem supportive in nature, he can pack quite a punch. He can use his Nature's Guise to pull of sneaky ganks, and even as a decent escape mechanism. His Leech Seed will keep his allies alive during skirmishes. His Living Armor is a great defensive spell that can protect teammates and slow down pushes. Treant Protector is also a formidable initiator, being able to lock down groups of enemies with Overgrowth.

Nature's Guise
Nature's Guise makes the target invisible as long as he or she is close to a tree, giving them bonus movement speed. The invisibility is lost if the unit moves away from a tree. You can also cast other abilities while in this invisibility, though other allies can't. With a duration of 60 seconds and a cooldown of 4 seconds by level 4, you can have a bunch of teammates invisible, letting you catch enemies by surprise. You can also use it as an escape mechanism as long as there are trees nearby. Since you can cast spells while invisible, you can throw out Leech Seeds at nearby enemies without them knowing, or catch them by surprise with an Overgrowth.
 * Ability: Target Unit
 * Affects: Allied Heroes
 * Duration: 15 / 30 / 45 / 60
 * Fade Time: 2
 * Tree Radius: 375
 * Movement Speed: 10%
 * Mana Cost: 90 / 80 / 70 / 60
 * Cooldown: 10 / 8 / 6 / 4

Leech Seed
Leech Seed will plant a seed in the target that drains its health while slowing it. The health will be drained in 4 pulses and will heal all nearby allies. It is your only spell that does damage, and while each individual pulse does low damage, all the pulses added together can take out quite a bit of hp, as well as healing you and other allies. The slow is also useful for chasing enemy heroes.
 * Ability: Target Unit
 * Affects: Enemy Heroes
 * Damage Type: Magical
 * Damage Per Pulse: 30 / 45 / 60 / 75
 * Movement Slow: 28%
 * Radius: 500
 * Duration: 3
 * Mana Cost: 140
 * Cooldown: 16 / 14 / 12 / 10

Living Armor
Living Armor gives bonus hp regen as well as physical damage block to the targeted hero or structure. The buff can be dispelled early if the target takes 7 instances of damage. The great thing about this ability is that it has the same duration as its cooldown, so as long as Living Armor is not dispelled early and you have enough mana, you can effectively buff a target infinitely. The buff is great for helping your allies tank through harassment and attacks and also slow an enemy push down.
 * Ability: Target Unit
 * Affects: Allied Heroes
 * Damage Instances: 7
 * Regen: 4 / 7 / 10 / 13
 * Block: 20 / 40 / 60 / 80
 * Duration: 15
 * Mana Cost: 25
 * Cooldown: 15

Overgrowth
Overgrowth will entangle all enemies caught in it, preventing them from attacking, moving, blinking or going invisible. Affected enemies can still cast spells. It is a decent initiation spell, even though it doesn't do any damage. As it holds all enemies down, it allows your teammates to focus down one hero without having to worry about others.
 * Ability: No Target
 * Duration: 3 / 3.75 / 4.5
 * Radius: 625
 * Mana Cost: 150 / 175 / 200
 * Cooldown: 70