You'll see Shaman enemies in Celica part saveral times. Shamans use Messiah spell to summon monsters. They don't move in a turn they summoned, and they dissapear once a Shaman who summoned them is defeated.
Conquering Evil Beasts
Dragon Zombie drops Blessed Ring. It restores HP of a unit who equips it by 5 every turn.
Pirates' Assault 4 & 5
Battles against Pirates and Arcanists.
Chipped Coral (You should get 4 or more for completing a sub-quest)