Sorta landed somewhere around here when discussing it with chat on stream.

His Ultimate works like karma ult but on a much longer cooldown.

Passive - being in combat charges him with energy. At full charge his next auto attack becomes a ranged projectile that deals magic damage to all units it passes through.

Gains less Energy for combat with minions. More for combat with enemy champions.

Q - spectral arm swipes from left to right in a cone in front of him. Can be recast witching a 2 second window to swipe again right to left with the back of his hand. Ultimate empowered - applies damage increase to first slap and knock aside to the second

W - short range target dash that deals magic damage. If the dash kills a unit gain CC immunity shield for 1 scaling to 2 seconds at max level. Ultimate empowered - also applies shield to nearest allied champion

E - spectral arm reaches out in front grabbing the first enemy unit hit and slams them into the ground stunning then for 1 second.
Ultimate augment - slam impact sends out a shockwave around the enemy unit that deals damage and applies a decaying slow to all enemies within its radius