New urgot may be the hardest counter to Kayn
Since urgot will build even tankier than now, rhaast will be the ideal form to kill him. But Urgot is also ranged, so Kayn will actually advance towards his blue form by fighting him. The more you fight urgot as kayn, the less effective against him you're gonna get. 2 weeks after releasing kayn, rito releases a champion who counters him pretty hard. Maybe.