The boosters each have hundreds of possible cards to unlock, and you can only open 8-card boosters one at a time
Number 39: Utopia Double can search out Double Or Nothing, and then you can Xyz into Number 39: Utopia with Utopia Double
As such, its a little challenging to guess the potential value of this card
When a player chooses to attack another player in combat, attackers and blockers are declared
Spells that were cast before Highspire Bell-Ringer entered the battlefield count
Doppelwarrior takes it further, enabling plays like: Librarian + Formula = draw 2, then Synchro during your opponent's Main Arcanite, to wall up with 2400 ATK, and pop 2 cards on the crackback Black Rose, to nuke their board at the end of their Main Phase Debris + Dandy + Doppel = 2-card Trishula Formula into Librarian Librarian Formula = Draw 5 Quasar All seems well until you realize there is a lot of hate that the deck is suceptible to, ranging from pinpoint disruption or devastating floodgates