for aelwyn, as always, it's adaine.
that's her baby sister. she's just a baby. literally 0 feet tall.
for damian... man there's a lot of canonmates i'd love that i know absolutely nobody plays. maya ducard, mara al ghul, flatline, respawn, emiko queen
the more like, realistic canonmates i'd love are obviously any of his siblings. cass and dick just disappeared so he's missing his family a lot. would also really love a steph, tim or jason in labyrinthium. other than that, his dad (you know, because their relationship is a clusterfuck), his mom, rose wilson, raven, maps mizoguchi, duke...
for chara, i think basically just sans and flowey.
for faith... spike would be funny in trench, angel, giles, anya, dawn. buffy herself would be great but it'd be complicated in a way i wouldn't want to inflict on anyone unprepared
for ianthe... lmao, i think any castmate would have trouble, but coronabeth would be nice