Top Lane J4: Revert His W
With the recent buffs to top laners such as Darius and the focus on keeping Jarvan IV as a viable laning opponent as well as a jungler, it is time to seriously consider reverting Jarvan IV's W.
The change to a W which scales abysmally based upon health debilitates him in matchups against opponents such as Darius, Riven, Aatrox, Nasus, Renekton, and even Kled, who while being hard counters (not Kled and Nasus but the others, Fiora is also a hard counter) used to be a lane where a skilled Jarvan player had a chance at outplay.
The W changes enacted as a knee jerk reaction to King Nidhogg's playstyle not only make his W less viable, they are counterintuitive to the rest of Jarvan IV's kit such as his similar effects on his ult from bonus AD as Riven's shield from bonus AD.
The reversing of this change to the prior flat scaling would be extremely positive and make more sense for the champion who was designed to be stronger early game and prevent the abuse of other champions with higher regeneration using this currently abysmal W Aegis Shield.