What are the rules regarding teleportation in the fic? Chaletwo was able to warp to the site of Leah's unexpected battle in chapter 51, so it seems like he doesn't have the same up-to-date memory-based restrictions as Felix or Xatu.
Chaletwo was blindly teleporting to the source of the psychic signal he'd felt, which is also a thing you can do. He couldn't have done the same without Felix's signal as a guide, and in turn, Felix could have done the same thing if Chaletwo had sent a similar signal. The other ways to teleport are 1) to a memorized location the teleporter has been to previously, or 2) short-distance teleportation, to a location within line of sight and inside a radius of perhaps 10-20 meters from the teleporter's current location (depending on the Pokémon's power level), which is what Felix did rapidly in quick succession to get them down to face the unicorns.