Two leaders and protagonist who while they may at times act like they know how to handle everything perfectly really don’t a lot of the time. They also started off as weak, scared and completely incompetent only to grow to become strong, less scared and only kind of incompetent.

They also have fathers (Boss and Rudolf) who they didn’t care for or even like much at all at first even if they had some soft spot for them but eventually they came around to loving them fully.

They are also members of large mysterious groups (The D. Clan and the Ushiromiya family)

They are both very quirky with exaggerated mannerisms and ways of speaking (especially fitting of a D&D player character lmao)

Both are very creative in different situations able to think outside of the box to try and get the upper hand whenever needed.

They both also lost parents while very young (William’s birth parents and Battler’s mother)

Their main powers (William’s devil fruit and Battler’s magic) is dependent on something else (William’s luck and Battler’s belief in magic)

They had circumstances around their birth (William being stolen as a kid and Battler being a bastard son) but while William took the information and didn’t care all that much Battler learning this took it harder

They helped out a girl (Doxie and Beatrice) who had old people they hated (Blue Blood and Kinzo) who they were at first very hostile with (William and Doxie arguing a lot in their first meeting and Battler initially hating Beatrice ) but they came around to them and accepted them as even family (William adopting Doxie and Battler getting together with Beatrice)

They also had siblings (Trevor and Ange) who while they didn’t recognize at first their siblings knew them much quicker than they did.

They would also be trained by much older more skilled individuals (Boss and Virgilia) in  things they had very little experience in (Boss teaching William how to use Rokushiki and Virgilia teaching Battler how to debate better)

Animation potential: So it’s pretty dang peachy! Battler can do so so much.  And so can William. And tbh both can honestly do damn near anything you want for a fight. William can legit roll a wheel to get any devil fruit power so basically: Want him to zip around as pure light? Got it!, need him to control gravity? He can do that!, Maybe you are feeling a bit spicy and want him to turn into a bull human hybrid?! Oddly specific but he got that! Battler has telekinesis, flight, reality warping, regeneration. For standard equipment William has his swords and guns pretty standard stuff. Battler has his own sword as well so fuck it sword fight. And William knows all of the Rokushiki. Meaning he can even bounce off Battler’s flight with geppo by walking into the air. You can have him use iron body to tank attacks from Battler and dish em back. Or even Rokuogan for a final attack on Battler since that be sick af. They can quite literally do anything you want William especially.

Debate: Yeah Battler takes this rather handily. In terms of speed they should be comparable in both are immeasurable. But holy shit the AP advantage is Outerversal vs Low Complex. William can’t stand to an outer mf even with all his haxs William relies heavily on his luck. He can pick and chose somewhat what he gets with cheating but there is no guarantee he will pick or even know how to kill Battler and most of his fruits can’t take out Battler so even with luck manipulation in small burst and supernatural luck there is to much Battler can do to get past William trying to kill him.

Battler vs William (Umineko: When They Cry vs One Piece D&D) “Truth Of The Gamble”