I need help with the legendary beasts

ive made it my mission to catch every single legendary in the game, and im currently trying to catch entei raikou and suicune, but they arent spawning (ive caught arceus already) so does anyone know any ways to run into them faster

I think you have to beat the elite four rematch before they will start to appear in the wild.

ive run into them before i rematched the e4 so its not that (dont ask why i didnt try to catch them)

if you know the level of them you can use repel trick by having a pokemon of the same level as them with a repel and going back and forwards through two routes

Don’t revive these old posts (called necroing) its not cool to do so. Also repel trick doesn’t work.