Board Thread:General Discussion/@comment-25983468-20160329120934/@comment-25983468-20160403233629

If I might take part in this whole Sans conversation. If he has this Determination, which I don't think, he is giving it up willingly. He doen't "use" Determination in any way. Never. No, not even in his fight. He is pretty strong and stuff, but once he is killed, he dies.

Undyne's Determination shows with her Undying form. Is Sans undying? Not in any way, shape or form. And there lies the difference. Undyne's Determination doesn't make her aware of anything, while his awareness of resets and timelines may have been the results of research. Once he was fully aware of those, he was even able to soundly remember certain things or atleast draw his memories back of deja-vus. I don't think he was ever able of anything like resetting, nor will he ever be. Also, he may not even have existed when Flowey first appeared.

Now to the Boss Monsters. Those Boss Monsters may actually have some teeny tiny sparkles of DT within themselves, due to their soul that exists post mortem for a short time span, but this amount certainly wouldn't let them reset of anything. It would have been well known and well used, if this was the case. And it kinda isn't. The first one to be able to do such things was Flowey -- or perhaps even Chara, who knows.