RPGM How did AsgarKnights animate their battles?

[Lurkermin]

I've been trying to reverse engineer how they pulled it off with their ROBF game series because I think it's incredible. But I've had no success, so I figured I'd ask here.

https://f95zone.to/threads/re-bf-v2-05-asgar-knights.103981/ This is a link to one of their games for reference.