Vex, Cheerless

Q. If my opponent has a Vex at a battlefield, do I have to pay [1] 1[A] to reveal and play a hidden Spell?

A. Yes. Hidden allows you to ignore the base cost of the card hidden. You still have to pay any additional costs, including the Vex’s cost increase (if the card is a Spell).

Q: My <<Diana Lunari>> is on a battlefield. My enemy moves a <<Vex Cheerless>> to the battlefield. I then trigger <<Diana Lunari>> and finalize it to the chain. I then want to play another Reaction spell on top of it. Do I have to pay the [1] 1[A] increase to play the spell?

Rules for Context - FAQ “How does HOT FEPR actually work?”, 322.1., 459.2.

A: Yes.