Who? �� If you're talking about me.. There's a ton of kids with the Destiny menu who give entire lobbies prestige master and/or deranks all day long. Personally, I only give prestige master to close friends or people that want to pay for it. And derank I do very rarely to shit talkers.

It's the same as doing a recovery. After you rank or Derank someone, they need to go into a game, get at least one kill, get the match bonus from finishing the game and then back out and sign out of PSN. When you/they sign back in it will have saved the rank/derank.

I've given tons of people prestige master with Destiny menu and it sticks if you follow those steps. Same goes for the derank.

Does it work in custom lobbies? And you can set any rank?

I haven't tested it in a custom game. The Rank option simply gives max prestige. You can't customize it, that's all it is