Yes I did, but I am clueless about the 3rd one. What should I do? T^T
I believe you're missing the purity ending. That is from putting all the names of pure characters into the eye of the void.
Spoilers for the names needed:
Drenth: You just have to accept the mark or whatever it's called when you meet him. Don't fill him with spawn.
Torgar: Do the purity path
Lukka: Just evolve your symbiote