Champion concept or Kassadin Rework

Haven't really though of base stats, although small mana pool and melee Passive While in the void loses 1% mana every second While out of the void, gain 1% total mana every 2 seconds Q (Normal) Next aa does bonus magic damage and marks the target Q (Void) Does same amount as damage and consumes the mark W (Normal) Dives (or transports) into the void, dealing small damage and marking all units in a small area. W (Void) Returns to the surface, putting all abilities with less than 2 secs of remaining cd to 2 secs E (Normal) Dashes to an unmarked target and marks them E (Void) Passive: if a enemy is marked, moving toward them grants movements speed and health regen Active: If the target is marked, stun them for .5/.75/1/1.25/1.5 and consumes it R (Both) Opens a hole the the Void, speeding up all allies and slowing down all unmarked enemies, rooting all marked. After 2 seconds, it detonates dealing massive damage to all unmarked targets, as well as dealing small damage and slowing all marked targets

So that's my idea, if you think we need less void it could be replaced with ocean

Any thoughts?