It only bugged me recently, but just the gameplay around avoid really gets on my nerves;
weapon triangle doesn't seem to do much and units typically get hit by sub-50 hit rates anyway, due to the RNG
and even then, all the player-phase stuff favoring enemies is annoying (line of death, weapon masters, certain blow berserkers).
Enemies having huge attack amounts ontop of the hit rates also discourages squishy units (rip azura, felicia),
so you're encouraged to cheese with tanks like Xander, who will eat the poison, seal, or shuriken debuffs anyway.
The devs really thought of how to screw us over with enemy placement & skills lol