I know this might become slightly controversial, but I don’t see the point in nerfing top creatures. People usually level them a bunch and pour a bunch of boosts down their gullets. Yes, they’re usually quite good, but nerfing them usually dumps weeks, usually months, of work, given Ludia’s track record with nerfing the top creatures.
So just make more counters. It’ll make more OP creatures less OP, and won’t wash away people’s work as badly. Part of the problem with Maxima, aside from IIT and the two rampages, is that it doesn’t have many counters, really only one reliable one in Thyla. So, if you buff the bleeders like Spinonyx, Spinotahsuchus, Daryx and Co. you’ll see Maxima become less of a threat.
Tl;DR: You don’t need to nerf something to the depths of hell, you just need to buff its counters.