Rules of the Game

Discard is the same as Flash.

Treat is an effect that applies to cards on the field just as it applies to cards in your hand. If the affected card is treated as a card with a different value that allows it to be placed in the Stack Zone, then yes, it can be placed in the Stack Zone.

In the case of Hannah Eclipse’s 10, it is treated as an Ace. Since all of her 10’s are treated as Aces, she cannot position them in the Stack Zone just like a regular Ace.

Should the Joker be activated while it is banished, it is at that moment that the user can choose the value of the card. Until the Joker has been activated, it has a value of 0.

Indeed it can unless Sylvester’s Ace is affected by Cannot Escape.

Before the activation of your opponent’s abilities in the Cast Zone, you can send a 9 from your hand to the discard pile to negate the activation of (S) Support type abilities in that Cast Zone.

No.

Harmony’s Ace activates two effects separately.

‘Cast 1 of your banished cards in a separate zone, and turn it into a (D) or (A) type ability with Ignore Def and Cannot Escape.’

This effect activates only if you have a banished card on your side of the field. If you do not possess a banished card, skip this effect.

‘During the End Phase for your turn : Banish 1 card you control from the Cast Zone.’

This effect applies during the final phase of your turn allowing you to possess a banished card.