I'm back, post time.
Idea btw, special dungeon shown to us by castle leaders later on, perhaps must be gone through before going to a dungeon to fight a boss character.
"Relic of might" cheesy name, can be improved later. My thought was this dungeon is shown to us by the leaders as it's our only hope of winning against some enemy. Very tough dungeon, 10 floors. At the end is a large relic ring with pedestals. These pedestals have every kind of mega stone. We all take one we respectively use, and they can only be used after an event of extreme rage or anguish, unlocking their power. Can be used at will after (if too op then they can be used only in events of extreme distress listed above etc.) this transformation lasts 10 turns and can only be used 1 time in each dungeon, time, and ease to use can be extended through vigorous training.
Just an idea!