my ideas for a 51 pt talent
Void
12% of your base mana
2 seconds cast
20 yard range
2 minutes cooldown
Summons a 5 yard radius void zone (lasts 5 seconds) that slowly pull all enemies within its 10 yard radius towards the void zone itself and reduce the movement speed and attack speed by 2% for every second the enemies are affected by the void sphere, stacks up to 5 times. Any enemies standing in the void zone loses 3% of their health every second. At the end of the duration, the void sphere implodes and deal 800 shadow damage to all enemies within a 15 yard radius and you gain mana equals to 5% of the damage dealt by the implosion. Only one void debuff can be on target(s) at one time, raid bosses takes 300 shadow damage per tick instead.
Or this
Void Sphere
5% of your base mana
1.5 second cast
30 yard range
10 seconds cooldown
Place a void sphere onto the target enemy for 5 seconds. The afflicted target loses 2% of their health every second and reduce their movement speed by 10% during its duration. If the target has a mana bar, you drain 1% of their mana every second during its duration as well. Only 1 void sphere can be on target at a time and raid bosses loses 330 health a tick instead.