About the "friendly monsters"

[H-Kazami]

The Friendly Monsters don't appear once you've given them what they asked for. ( I think)
If you got the Diamond from Garuda, and have done the others, give it to Yan on Vile Island.

What do you mean by Reset/Exit the Game? Why do you have to do that before you meet Yan.

I guess I wasn't clear on that. What I mean is that what happens if I save and exit the game and play next time? Does it affect anything?
Because right now I've encounted all 8 of the "friendly monstesr", and I've given them what they wanted; however, when I gave the stone to Garuda, I gave 3 stones that he wanted before he asks me, then he replies with "......" 3 times, and then ends the battle. Now when I met "Yan", it keeps running away asking if I met the others yet or not.

EDIT:

By the way...I was wondering how long does it take to encounter the "friendly" Garuda

Right now I have 2 Diamonds I think, one from Garuda, and the other one is from somewhere?(I'm not too sure about the amount of Diamonds that I have)