Ah, there lies my problem. Despite being a year in, I'm still not overly familiar with all types of fish and what may or may not get along with what, hence the thread, and a lot of fish people seem to like, butterflies and such, just not a fan of. Already some of my favourites are out based on edibility, rarity or cost.
A foxface, perhaps. Neat fish, spines to keep it safe, and would hopefully help control nuisance algae since CuC will be limited by the eel/trigger.
Would love to get my Marine Betta a mate, but that has a whole host of challenges associated with it. One concern with these ones in an aggressive tank is their big fins getting torn up in fights. So far hasn't been an issue, but aside from the eel, it's the biggest fish I have.
In my looking for fish that fit the general requirements, larger, semi-aggressive/aggressive, I keep coming back to tangs, though I do believe there's a good probability of murder happening keeping a bunch of different tangs.
My aforementioned friend with the Purple is trying to get me to take his Tomini too. Apparently gets along fabulously with the Purple.
Convict Tangs would stand out amazing against the mostly darker colored fish, and have heard they can have some interesting behaviors.
Looking at the Rhinecanthus genus Triggers, the Bursa is a neat one, though somewhat concerned about the logistics to feeding two Triggers properly. Haven't seen in shell clams in months. Fresh or frozen.
Same with lions, dwarf fuzzies are one of my favourites, but between my previous failure and their being more than happy to devour my fish (let alone the proper diet!), I'd be hesitant to give it a go.
Spanish Hogfish was recommended to me. Sounds like one might be a good fit, especially since again, CuC is already a no go for the most part. Interesting that they supposedly will eat parasites off other fish.