Made an account just for this bug report.
Earthquake on the Giant is extremely bugged, it often leads to the boss somehow overflowing their hp and being unbeatable. (You can test this on the final boss and the Paladin by spamming her and mostly her)
It also leads to a crash against the final boss VERY often, not sure exactly why but it may have something to do with canceling the attack animation.
Here's an easy cheese for it, 4 Kitsunes at front stacking up power ups, Minotaur spam holding her back in the middle while you MAKE SURE to feed her the meat (Don't use Giants, they'll crash your game) and Shohos at the back providing buffs with maybe a Kitsune guard for them, keep some Sho-Mings on your selection pallet in case shit goes wrong. Easy Cheese.
But it won't really help you, last and final bug(?), there is no ending cutscene even at 1.5.9 even though patch notes seem to imply there is one. The level gets marked as complete but nothing happens and the "Story Only" button doesn't update.
Edit: Two more bugs I just remembered.
1. Ninjas can't be fed to upper units manually.
2.If any prey is eaten after a level ends, it shows one more reward. Not sure if you actually recieve it. Ex: The level ends 85/85 eaten, if you feed your units a Cho-ming before picking it up, one more reward will appear. This also works if you keep a boss that spawns them infinitely last.