Landorus won't appear

So I have Thundurus with me and I’m at Rezzai Desert entering from the bottom of those rock formations and he won’t appear, I have tried for 1h now. Any ideas why he’s not appearing or what I’m doing wrong?

Did you already catch tornadus?

No, not yet. Do I have to catch them both before that?

Yes, I believe you need to bring both to the Rezzai Desert to summon Landorus.

Thanks. So thatr would mean that is the same for Keldeo then, right?

Yes you need both thundurus and tornadus to get landorus, and the trio to get keldeo.

Thank you very much. I love this game, but I feel the post-game is really unclear about what you have to do

There’s a legendary guide on these forums, plus tons of other ones. Just look around when you have a question and you’re sure to find an answer

Well I’m referring more to things plot related, this part was just unclear to me. Btw, since I actually looked all around and couldn’t find, do you know if the Reveal Glass has been released yet?

Definitely is in the game, I believe I found it next to the house where darkrai is in the nightmare badlands