The Forgotten Shard feels more susceptible to debuffs for me, and I had plenty of other items to use when my energy was close to giving out like mana/burning leaves and roots. Just as long as I kept the defense buffs and attack debuffs stacked, so much as using weakening slash multiple times when it kept self-buffing, it kind of clicked. I could have been REALLY lucky since the boss kinda forces you to make an attack with 1 hp, silenced and sexbinded, and all items destroyed once you get it down to that point. And I still had a Givini Potion in reserve until that final clutch moment.
All the bosses have a kind of trick to them, really. The first you have to heal every other turn while freezing it. The second I found you have to debuff its speed constantly and then healing one time by spell or else you get silenced. Third one you're better off using the mp to heal before fighting because it drains you, and then whack it with Nalili's skill. The fourth (bane of my playthroughs) seems to require you to buff yourself to wade through its attacks than just picking the right equipment build (I was half-tempted to give myself one of the easy route items via cheat if all else failed). And the last one is like a final exam that FORCES you to use items in battle, and to see if you managed said items well enough because you'll need to use them to recover at least MP.
