A) it has a vision range like Twitch's.
B) it only gives the health regen if you're not in the vision range
C) I'm pretty sure the vision range is equal to the standard adc auto range of 550
D) it only lasts 5 seconds
Make the vision range larger? That's something I can understand. Maybe less initial movement speed (it decays I think over 1 second)? Maybe. But I don't think it needs a charge up time.
Even Twitch's charge up time was added before it was changed to camouflage because it was too powerful as an instant stealth. It also later got added to it a longer charge up time if he was taking damage because, if he got into the stealth, he was free. There was no counter other than just having a pink in your inventory and trying to force him to stay in it. This was removed with the stealth update because the pink counter was naturally built into the stealth. Similarly, if you put a pink in one of the lane brush, pyke can't get the health regen unless he reveals himself by killing the ward.