Sei is part of the generation before Rou. She was a hobgoblin mage when first introduced into the story. She later becomes the leader of Agony.
Re:Monster
Tomokui Kanata has suffered an early death, but his adventures are far from over. He is reborn into a fantastical world of swords and magic-- as a lowly goblin! Not content to let this stop him, the now renamed “Rou” uses his new physical abilities and his old memories to plow ahead in a world where consuming other creatures allows him to acquire their strengths and powers.
