the sumo bro creates lightning at it's center of mass, which doesn't account for big sumo bros. sadly, there's no way to fix this without creating your own sumo bro, as this offset is hardcoded into the script.
copy the sumo bro code from the basegame into your episode and give it an id within the custom range (751-1000). rename the sprite and txt file to match that id and then go into the script, go to line 104 and replace
with
which is not ideal but should work for your use case. (also if you care about having it look nice in the editor you should make an ini file for it too)
enjl is the one that made the sumo bro so if you yell at him enough this might get a more proper fix in the next update.