>>34416692Legendary mons from the story are shiny locked since gen 5.
The Zekrom and Reshiram that Hilbert and Nate meet at BW/2 were canonically non shiny, the Groudon/Kyogre and Rayquaza Brendan meet at ORAS were canonically non shiny, the Xerneas/Yveltal that Kalm meet was canonically non shiny, the Cosmog, Necrozma, Zygarde and Tapus that Elio meet were canonically non shiny.
It's not that hard, kid, just wait for a game in which Zygarde wasn't actually there (yet it appears to allow the player fill the pokedex) so they aren't forced (lore-wise) to shinylock it anymore