Yeah, as far as Iris being in her potential special goes... it could work. Iris' special ends with her chasing after Rayquaza,
but we don't know where it was flying to. xD
Yup, if he's brought out, it's pretty much gg for its opponent. Supreme King Dragon Zarc can't be targeted or destroyed by card effects,
and if it's placed in a Pendulum Zone, your opponent can't use their Fusion, Synchro, or Xyz Monsters' effects. xD