slime builds can be really overpowered if you get them to max level, especially with coolant slime and blueberry slime
I'm not saying this as a bad thing, it's fun to be overpowered, and the slimes show up infrequently enough that I don't think it's an issue at all, but I don't see many people talking about it, especially with hidd1212's list completely ignoring any slimes (though everything else there is pretty accurate and useful)
the biggest reason that blueberry and coolant slimes are so powerful is that they have a purely negative effect on their target when added, and a purely positive effect on their target when cast, so when you add them they always apply a negative effect to your opponent, and then if you overflow with them you apply the positive effect to yourself. Since the effect is pretty weak at low levels, I can understand people maybe not wanting to go for slime builds since they can be hard to get going, but they are definitely worth it. Almost all of my successful builds that I can think of have been at least partly slime-based