So I've cleared Legend mode and most of the Adventure map, and suddenly a Trial mission teaches me that special units have weaknesses to certain items? Stuff like moblins being weak to bombs or flying units being weak to hookshots. Blew my mind that it never came up before. I wonder how much easier I could have made it for myself had I known this sooner. The hookshot one kind of makes sense, and flying dagronmans are usually a huge pain in the arse with some characters.
The items work, if you use them on the enemies when they are doing their most powerful move, indicated by a greyish aura and sound cue. If you use the item the enemy is weak against then, its attack will go haywire, possibly damaging itself and exposing the weakness gauge. You can also interrupt them easier with said items, but that's not all that helpful most of the time.
So I just started Adventure and is there some trick for those Ruto stages with a bunch of bosses chasing you and you need to kill X many enemies?
Ignore the bosses. If you kill them while killing grunts, that's nice, but otherwise they take too much time, especially when you have to eliminate 700+ enemies in 10 minutes. The boost in morale affects attack damage, not defense, so if you dodge well it shouldn't affect you. Run from enemy mass to enemy mass, try to keep a distance between you and the giant monsters and spam your attack with the widest area of effect while dodging stuff. If you're lucky you get a bomb upgrade, helps a ton.