Shiny Mewtwo

Any advice for catching shiny Mewtwo any pokemon you'd suggest and how to prevent him from killing himself? Pls don't say use master ball I used it on soul silver to get shiny ho oh (killed most of my team lol) so id have to do it on HeartGold I think I have it if not I'll restart unless y'all have great advice. Another thing I'd prefer not to rng a shiny perfect Mewtwo I want a real reaction when I see it