This is a very, very interesting question 👀

So: Fitting with the Summer theme, I think a beach grill-off is the best way to go about it. Percival recruiting the other chef-type Servants into the biggest cooking competition in human history!

But also, the swimsuits let him see... god damn, some of these bitches are scrawny af, aren't they?

I think it would be fun to pair up Percival with Emiya for this event. Emiya's good at cooking pretty much everything, while Percival has stated in the past that he's only good at a few dishes. These two hunks running around trying to feed up some of the scrawny characters, hell yeah.

I don't have a full roster of who would be affected, but I think giving Gudao and Gudako a "got fat on vacation" mystic code would be fun.

Also, Xu Fu is canonly underweight and should get fattened up by himbos.

Summer Scheherazade (Fat) would be incredibly hot to see too.