Great! :D

Ruca's past life is complicated, but I guess I should explain that even though he was a demon-god in his past life, he doesn't actually see that fact alone as something bad. In the world of gods, there were two fractions formed that were fighting against each other. One was Ratio who looked more like geek gods and the other were the Sensus who looked more like demons. Asura (Ruca's past life) was a general of Sensus and he lead the army to eventual victory and ruled over the Heavens (the world of gods). For the gods of Sensus, Asura was a hero and Ruca also admires him a lot, because he wasn't a bad person at all.

What Ruca is afraid of is that the people who are reincarnated (Avatars) are discriminated against and feared in his world. If an Avatar is found out, they are arrested and either taken to laboratories to become experiment subjects or they are taken to war to fight, promised that if they'll be good and don't die then they might get their freedom back one day.

Ruca is also thrown onto the battlefield when he and his friends are captured in the beginning of the game :(

tl;dr his life is complicated xD;