Chirin no Suzu/WMG

Wolf was a Death Seeker
Analyzing what he had said in the end, he said that he was glad that Chirin was the one who killed him. He also said that the greatest thing a wolf can have is death in battle. Now, taking those two bits with the fact that Chirin telling the wolf flat out that he was gonna kill him and it creates this little theory: He decided to raise Chirin so that one day Chirin could kill him and this give him a good death.

Wolf actually pulled a Johan/Legato on Chirin
This could be the alternate theory, as it doesn't seem out of place compared to what those two end-game plans were. Having someone kill him and thus break them completely with that action. He raised Chirin like a son, then has Chirin raid his 'former' home, then goads him into attacking himself (well, not intentionally) by doing the work for him. This takes the whole "I'm glad you killed me" thing to a creepier level, as this translates to "Good. You killed me. My plan is complete." His own death, followed by what happened afterwards, completely crushes Chirin's own spirit... again.