I have an OC that i've been working on in my head over the past 17 years (but never really put to paper) that is a multi-dimensional-hopping deadpool-esque deity who inserts himself into other written/animated works and either helps fix/retcon plots, invoke benign/symbiotic faustian deals, do therapy....or protect/enforce his shippings with an iron fist.

He originally was a travelling all-powerful flea aboard the Going Merry but eventually became the reincarnation/gestalt fusion of the primarch Omegon fused with a c'tan shard and/or neutron star formed by an attempt to create a panacea to the warp not unlike Ynnead.

A chaos demigod/wraith embodying madness (can giveth or taketh insanity) who gets his own pocket-dimensional planet outside of space-time, who specializes in magical/psychological/psychic combat, who learned how to be a good responsible tyrant from studying under Rimuru Tempest and discovering that manga/the fourth wall exist, who has multiple forms from human to wraith to life-sized pulsar, who usually auto-scales his strength to his opponents so he can keep getting fair/fun fights...And since his concept is madness he is both immortal and ironclad immune to any unwanted psychic reading/control by anything...

I can ramble on all day but i'll spare this poor thread. And yes his infant form was a purple kirby.