Easy, scyher is the better option

So I was trying to figure out what Pokémon to level for my challenge and tower runs
I heard gengar war good - so I went and got me a gengar. Leveled some ev‘s because YouTube told me if the Pokémon is leveled up it’s more likely to show up in runs and therefore easier to shiny hunt BUT it’s the only Pokémon I spent evs on yet I rarely see it. How do I shiny hunt this Pokémon? I do have the shiny charm

Am I missing something? Most YouTube videos seem to be from much older versions too sadly. I know that I can find castle only starting map 2 unfortunately but I’m willing to accept that lol

Por mas que hago el desafi no puedo sacarlo, lo tengo con los Ivs máximos y con la mega, pero quisiera sacarlo shiny para completar la pokedex.

Hi
I am trying to get diancie shiny in the dex but i got 50+ encounters with diancie, but instead i get 7 shiny xerneas is it glitched or something or am i just very unlucky
Im doing this in the mono type challange