I have seen surprisingly little content of these two but honestly I think this is such a good ship 🩷 in general I think pillarmen x human ships are very underappreciated and these 2 are probably my fav variant of them so like... Teehee. Also since you didn't specify I assume you meant headcanons...if not then I apologize but these were fun to make anyways 🙏

- Both of them absolutely hate the way they sympathize with each other. Caesar feels guilty for secretly wanting to protect something he knows he has to destroy, and Wamuu desperately wishes he could brush off Caesar the same way he would brush off any other human

- Wamuu has always envied humanity's ability to build families and grow old together, because literally everything he's ever known has been combat and survival of the greatest.

- Neither of them want to be the first one to admit that they care. Every time one of them is hurt, the other one panics and wants nothing more than to double check that they're ok, but they always go straight back to pretending that they don't care at all

- Wamuu isn't great at giving compliments, in fact they're usually very blunt and matter-of-fact, but Caesar still melts every single time - and Caesar is pretty dramatic about it, even when it's the least romantic sounding compliment anyone has ever given, because he knows that what Wamuu lacks in dramatic flair he makes up for in pure sincerity

- Caesar is a very affectionate person, in a typical melodramatic romance way (I mean that part isn't even really a headcanon). Wamuu on the other hand really, really doesn't understand what on earth Caesar is doing with that stuff, but he finds it endearing anyways. In general Wamuu doesn't understand human flirting, so he'd spend a really long time thinking Caesar is just being really really polite. Also just in general it's a constant loop of Wamuu not understanding why humans do certain things, Caesar doing those things and Wamuu deciding he likes them (though he's silent about his appreciation)

Ah late post today but I really hope you enjoyed this anon! I really liked coming up with these, and god it's been a while but looking back at battle tendency, the tension absolutely was there between these two