Marcus_Black_3584
Its good that you decided to change his martial soul, this way you can develop a new path for him, and not follow some spirit rings that appear in the cannon. and the mutated version of the white tiger is a good choice, its not too OP, it makes sense that he has it and you can integrate the light element of the necromancer with it.
it's good idea to make Three Eye White Tiger become his spirit, maybe when he make contract with Tian Meng (he will be spirit soul, not conscious ring). with spirit power of one million spirit beast and his own attribute of Death Light, it will trigger his bloodline and make his spirit to evolve. But than White Tiger, i think that Holy Tiger or Demon Tiger more fit for him.