RIOT, Vel'Koz should steal enemy/allies abilities. (example enclosed)
Being that Vel'Koz is a creature that seeks infinite knowledge, specifically that of his foes, would it not make sense that he takes their abilities?
Example:
A way of doing this could be that his R would reveal all nearby enemies (and allies) and then he could use his q,w,e to steal their q,w,e. I assume if Vel'Koz went with this ultimate ability it would act like 
Kog'Maw's ultimate in that each time it is used in succession it would use more mana, and then have range like 
Xerath or 
Twisted Fate, and be unlocked from level 1 similar to 
Karma. Casting it on an enemy champion would damage them (and or slow). Where casting it on an allied champion would heal them (and or speed up).
Upon death all of his abilities reset back to their base state, or they could be kept.
Other possibilities:
-Upon killing an enemy champion he may steal one or all of their abilities of his choice. -Upon killing an enemy, the last ability they used replaces his respective ability. -When abilities are not stolen or Vel'Koz dies, abilities reset to his normal/current abilities.
