To be frank, the problem with that explanation for me is just that I'm not seeing how, from:
> Became a berserker, had to train to control it
> Grasped inner peace, communed with the elements, got his RM, yadda yadda
We get to:
> Psychic trap on his mind
> To hold himself back
> But also works on intrusions into his mind
> Oh and it's unbreakable so he can never go berserk and insane ever