I think I'm gonna use Elementalist. Mind specifying what kind of spells he has Angry Bovine?
Sure. Just use appropriate numbers for each ability. I'll assume you want 5 abilities, 4 basic and 1 ultimate. If you want to change any of them, feel free.
Storm Surge [High Mana] - Deals X initial damage to the target, then causes him to explode in lightning, shooting out Y (I would pick 3, or increasing depending on ability level) chain lightnings with the main target as the unit.
Gift of Slates [Passive] - Grants the Elementalist protection in the form of thick rock armor. Reduces damage taken by all physical and spell damage by X% (a low number would be good), while increasing physical damage dealt by 2X%.
Magma Blast [On Cooldown] - Blasts the enemies around the Elementalist with molten wrath, causing them to be set on fire and take X damage. While on fire, they take another Y damage over 4 seconds and run around disorientated and slowed. (For the last part, remove control of the character, and make it walk back and forth while under the effect of an ability like slow/thunderclap.)
Sonic Burst [Low Mana] - A burst of wind steals the breath of an enemy, causing Y damage (which should be low, the damage is not the primary motive for this spell). If the target wasn't casting an ability, he is silenced for X seconds. If the target was casting an ability, he is silenced for X seconds and stunned for 2X. (X should be a reasonably low number, 2-3 range is good. Anything higher starts getting insane, and you'll want to keep the stunned number just higher than the silence. I assume that some spells have cast time with this ability.)
Elemental Fury [Ultimate] - Granting the powers of the elements upon the caster, the Elementalist, increasing his movement speed and attack speed immensely (amount is up to you, should be relatively high because of the short duration) for 5 seconds. After this effect expires, he splits into 4 primal elementals: Air, Fire, Water, and Earth. (Like the pandaren's ultimate, to an extent.) Each one of these elements has a more powerful version of the elementalist's abilities, with the correct associated type.
This was a quick jot down of whatever came to mind. I'll think of more if it's needed.