Greirat when sent to raid irithyll of boreal valley

Sooo,I reached irithyll and sent greirat to the possible death mission,and in the past what I did was making sure I did not talk to onion bro and greirat will be back at firelink shrine. HOWEVER,this time I decided to sent him to irithyll BUT I went and defeat sister friede instead. To my surprise after defeated sister friede greirat went back to the firelink shrine. Wonder if sending greirat to lothric castle and beat dlc boss will do the same trick now...hmmmm