That ability lets you pick once from four different effects: tapping or untapping a permanent, dealing 3 damage to each opponent, copying an instant or sorcery, or (presumably your last choice) putting Gandalf back on top of your deck
HERO Beat could summon a rank 4 Xyz monster with Bubbleman and another hero, then banish both of those monsters with Miracle Fusion to summon Absolute Zero
In that case, they perform as much of the action as is possible. If you point a Lightning Bolt at your opponent, and you have Davros, Dalek Creator in play by your end step, your burned foe will have to face Davros' villainous choice
As winning players usually receive Play
While I miss making my own sound effects when I send baby dragons into battle, and dabbing hastily at cards Ive spilled cider on in my excitement, Arena builds on the lessons learned by the rest of its genre, and takes away a lot of the friction and fuss that I will (grudgingly) admit exist in its paper incarnation