I knew him too. Not well. He was one of the groomsmen at the wedding. I should say groomskitten.

I believe having reminders of those we've lost can be good even when they hurt, but I understand how that makes the situation more complicated. I'd also like to point out that this makes your particular situation less normal than it does for the rest of us. Of all the kittens to find you, it had to be the one that looked exactly like Luke.

If you really wanted, I'm sure we could find some way to keep the kitten away from you. But you should seriously consider keeping it.