Bard was created to keep ADC's in check.
Ezreal: Stop stealing cs! Bard: I took one that you weren't going to get.. Ezreal: Noob Bard: Fuck you i'm out I got chimes to collect. Ezreal: No wait please come back.
Ezreal: Fking noob peel the enemy off me. Bard: uses portal C'mon guys and get your free kill on my adc. Rides on me! Ezreal: OK I"M SORRY!
Ezreal: omg noob bard can't focus. Bard: ults him I'll serve you our adc on a gold platter. Ezreal: F*ck im sorry help!
Fck with bard and he can fk your entire game up.

)
, technically top lane.