Board Thread:General Discussion/@comment-6747658-20130401084750/@comment-42.98.41.92-20140405130943

From what is available, SF definitely knows and hates Big Boss and Zero so much that he wanted both of them dead. Big Boss is around 40 in MGSVGZ, so he'd be just 10 when WWII concludes. Zero is much older as he served with The Boss in the SAS in WWII. Now SF's motivation for revenge seems to have something to do with his sufferings from WWII and the lost of his country, language, etc. Let's not forget, we are talking MGSV -- I wonder if Code Talker -- possibly a member of the Philosopers who secretly survived are in some ways involved.

In any event, remember that we only see parts of these characters' whole life. Many things were not shown on screen nor even mentioned. The room for Kojima to expand Big Boss' back story is still at large and I don't think it raises eyebrows if SK turns out to be a new character.