Kai's method of acquiring bloodlines, like transplanting, has a major side effect. Using foreign objects as a base is not the perfect solution to obtain bloodline abilities.
Although this method is not recommended, it is entirely possible to acquire a bloodline, with consequences.
The consequences are losing one's sanity, a sudden mutation on a certain part of the body, or the body might collapse entirely.
Kai's transcendent foundational ability was Self Sovereignty. With this ability, everything inside Kai's body completely belongs to himself.
Only by using this ability did Kai remove the poison that Anna used on him. At the start, due to a severe injury, he wasn't in the right condition to use it.
But after getting a little better, he used Self Sovereignty to remove the poison.
'Now, it's time for the second test.'