>>56787844I think it's because it's probably the worst one with Mamoswine, Dusknoir, and Licklicky following it up.
Honchkrow is a bit different, but is at least still working with the crow theme constructively and looks mostly congruous. Magnezone is a progression where the individual Magnemite in Magneton have merged together which is reasonably logical and helps reinforce a parallel with Metagross which is another steel type with similar physiology. Togekiss is just the angel egg bird filling out to a fluffier angel egg bird, and Snowrunt already has a "freezing child in the cold" thing going so honestly Froslass doubling down on that is more fitting than Glalie is some ways. And Tangrowth is just More Tangela and Yanmega was bigger meaner Yanma.
Dusknoir though has a far greater visual disjoint from the more washed out and layered shape of its previous evolutions being almost all one piece with details stamped on, which starts in Gen 4 and becomes a massive problem later on, and goes from generalist, spooky ghosts to being some kind of undead military commander. Lickilicky is the same but with a simplified body so it doesn't feel like a progression either, Mamoswine completely fucking hard pivots into being a completely different pokemon with an ugly clown face and distinct limbs, completely in reverse of what its priors were.
Rhyhyperior though kind of does everything wrong, switching color palette, introducing a new, now completely incongruous design concept, big and often awkward physiological changes are are kinda weird. and its visual progression is jank as hell and manages to be more jarring than Electivire's which is impressive given that the electric muppet is literally the original "what in the fuck even is this thing supposed to be" pokemon.
It'd unironically work better as a mega and almost feels like one since random new weapon limbs and entirely new concepts or clashing design elements are actually pretty common among a lot of Megas.