I'm working on a game I've started and stopped development on a few times which is tentatively called VISIONS: New World Rising. It's basically Yu-Gi-Oh the RPG, and combat in the game is handled through the use of a card game that's designed for an uneven number of combatants on both sides, to allow either 1v1 matches or the entire party to fight together as a team. The game also has support for custom card creation by players, with players being able to point-buy abilities for their ace card and create cards unique to them, and effectively allows you to play through a card game anime.
Both of your ideas sound super cool and I cannot wait to see one or both of them!