And something I had been thinking for a while. If you want to adapt the Nasuverse to TRPG terms, why not use Anima instead of D&D. Most of the things you are trying to adapt are already adapted there, and it has already something called Eyes of Death (although they are way weaker than the Nasuverse ones, but still). Unlimited Blade Works can be created with one of the illusion spells of that game (given, it's the highest level of illusion magic, but that works with Reality Marbles being the greatest magecraft any magus can do that isn't True Magic)
It even works with mana points and all that, and with thousand of points of mana, at that, at higher levels.