MasterReigen
The spark shouldnât be changing his race. You defined it as simply having the highest potential itâs race can have. In this case, itâs the potential of someone who is mostly human aside from 0.39% Isu. Thatâs it. Itâs not going to purify his bloodline. The other assassins with other abilities may have had more of the Isu bloodline than him, so even those added abilities may not come to fruition.