The best example of a movie I have on that I mostly enjoyed except the ending is Wonder Woman.

They could keep the CGI-filled studio mandated fight if they want, but then make Diana realize it's not making both sides stop fighting each other. They just keep on going.

Here's a how I would do it without any further thought but the 30 seconds I spent writing this comment: There's a zoom in on Aries as he laughs, telling her he told her so, it wasn't him, before he disappears, saying he'll return, empowered by the endless war of humans. Diana realizes she can't punch her way out of this one, and she'll have to use love (it's a classic WW theme), love for humans to make them see the love for each other. Love isn't easy, it takes time. So she's going to have to stick around in the world and fight the long fight, this won't be a single villain she can kick the butt of.

Idk, something like that. Point is, the whole end fight scene shouldn't imply war is caused by a single evil Greek god.