>>73383551My opinion from what I've seen:
-Easy: Really good collab partners, mesh well with almost (if not all) personalities. Can help carry a collab and make it not boring, won't have awkward silences, knows how to talk with other people, respects the host. (Alpin is a guess since he hasn't collabed with anyone but I get a hunch he'll be an easygoing guy).
-Cool: Good collab partners, they're averagely well at everything. Might not mesh well with everyone, but when they are with someone they do, the collabs are amazing. Funny and entertaining, they do well. Could have awkward moments/silences at times but won't be anything noticeable.
-Tricky: Could be hard, they might do well depending on the game and/or topic of conversation, but is a high risk it won't go well otherwise. Some of them might just be hard to understand in general (The ESLs like Rura, Mana, Charley). Some need to practice more social skills, but they mean well. Some are potential landmines of edgyness that could push them into Hard tier but they have restraint most of the time (Kuromaru), just avoid certain political topics. Some have very specific obsessions or topics they wanna talk about (Lava) and if you don't know them that well, it's not gonna be fun for either of you (but if you're gonna collab with someone like Lava, then you should like the kind of shit she talks about in the first place). Could lead to a lot of awkward conversations, silences.
-Hard: Final bosses of collab. For some it's their accent and difficulty interacting with others (Ex: Olga, I assume that's why she doesn't do collabs), but for most its: unhingedness, lack of respect for the host, general social stupidity, lack of self awareness, need to be the center of attention and talk the most, lack of energy, not wanting to talk much at all, and/or they act like they don't wanna be there.