I like to make up champions for fun, still unsure about his abilities but lore-wise he was afflicted with a curse that slowly infested his soul and body and eventually caused him to lose his legs and right hand to the infection.
To hold back the effects of the curse he must trespass into peoples souls and steal their very essence. As a result of this he has gained various spectral abilities along with his arm mounted cannon on his right hand stump
* P: Spirit Leech:
Every 3 basic attacks or each time Obasi damages an enemy with an ability, He applies a stack of Spirit Leech on the enemy. At 5 stacks of SoulSate, his next basic attack steals X amount of health and magic resist (resistance steal wears off after 5 seconds) from the enemy.
* Q: Essence Cannon:
Obasi sacrifices a small amount of health and mana to fire a blast from his arm cannon. If the shot impact an enemy, the health cost is refunded with a 25% bonus and a stack of Spirit Leech is applied.
* W: SoulStrike:
Obasi charges his mechanical legs for .25 seconds and dashes forwards. Dashing through enemies deals magic damage and applies Spirit Leech. If Obasi charges through an enemy champion they are dragged with him a short distance and a soul fragment is torn from their body that temporarily holds a small percentage of their resistances and health for 4 seconds, then the stats are given back to the enemy.
* E: Spirit Surge
Obasi opens a short portal tube in front of him for a few seconds. Obasi may walk through the portal with high movement and untargetability but cannot attack. Obasi can reactivate the ability to close the portal early. If enemies are standing in the portal zone when it dissipates, they are stunned, take magic damage and have a stack of Spirit Leech applied.
* R: Arbiter of Self:
Obasi may cast his ultimate only on enemies with 3 or more stacks of Spirit Leech applied to them.
Obasi rips X number of fragments of his enemy's soul from the body, depending on their number or Spirit Leech stacks. After 1 second, Obasi can recast Arbiter of Self to fire a bolt of spectral energy from each soul fragment to a target location, dealing %hp magic damage and healing for a portion of the damage dealt.