New Zilean passive on PBE?

I haven't really played zilean, but I have had him on my team..

Old Passive- Zilean and nearby allied champions gain 8% additional experience from all sources.

New Passive - "Time in a Bottle Zilean stores time as Experience at a rate of [2/3.5/5/6/12 at levels 1/6/11/16/18 based on level] per 5 seconds. When he has enough Experience to finish an ally's level, he can right-click them to impart it. Zilean receives as much Experience as he gives. Cannot be used in combat.

so like level 5 comes at like around 10 minutes.. and if zilean's experiance keeps stacking.. that's like 240 experiance.... Which if you hit level 5 before the enemy laners and the XP needed to get from 5 to 6 is about 448 you may be able to jump to level 6 if you use it when you're just about half way to level 6!

I'm not sure what to think, but I think this is kind of cool! Okay Immagine you are botlane.. with your zilean support. You hit level 5 before the enemy lane and as soon as they hit 5, your Zilean gives you experiance to get level 6 and the enemy lane is pushed up a bit..

TIME TO ALL IN!

#What do you think?

Idk if this is a nerf or buff but that surprise level up may surprise unsuspecting people eh? :3 Probably plan a gank at the time too..