Actually wouldn't Adrenaline cause the Lion to attack the target once and then repeated attacks would target the opponent?
Cost wise it's not too different from Eagle Eye, except that Eagle Eye can attack target for three damage, and attack the opponent for 5. It's a bit lower powered, unless it was in a element that is lacking in CC.
My question is why Time? How does this fit thematically with Time? Wouldn't it be more thematic with the initial cost being Life and then some other quanta to trigger the attack? Maybe Gravity or Death, or even just more Life?
I could see it being used in a mono-Life deck if the costs where all Life.