Plasma Blast is WAY harder to resist than Double Retribution. The slower Crystal Worms (like Caeruleus or Roseus) can tank a Double Retribution from Jaguardian, most legendaries with rounded defence or more can tank one hit from it.
Mythics can tank that even more easily, and they’re getting more and more widespread with each Fortune Shrine. It’s still a hard-hitting attack but definitely manageable.
Plasma Blast ignores the defence stat, which means you can only tank one hit from it if you have the element advantage AND sufficient HP (I think basically all Earth 5★ will die from a Plasma Blast anyway).
Also the free 5★ reward monster Wavetail is definitely more common than 7★ Kanna
Despite everything though, there’s still a Cannibalize nerf I’d support, which is making Cannibalize unable to target self. Needing to sacrifice a 2nd monster, instead of already having all the core monsters already in your FL, would make the strategy at least a little less efficient + it doesn’t make sense for a monster to cannibalize itself 