Q2320: When paying the [Call Cost] of "Topfist Vainglory, Brawlzeus", which player chooses the Gauge to be paid out?

A: The player who called "Topfist Vainglory, Brawlzeus".

Q2321: I declare the call of "Topfist Vainglory, Brawlzeus" while my opponent has exactly 2 Gauge. Can my opponent cast "Begone!!" in response to my call?

A: No, they can't. The [Counter] Timing for a call occurs after all costs have been paid. When you pay the [Call Cost] of "Topfist Vainglory, Brawlzeus", your opponent will only have 1 Gauge remaining, and they will not have enough Gauge to pay for "Begone!!", so it will not be able to be cast.

Q2322: When paying the [Call Cost] of "Topfist Vainglory, Brawlzeus", which player chooses the card to be put into the Drop Zone?

A: The player who called "Topfist Vainglory, Brawlzeus".

Q2323: Can my opponent choose to keep the card I chose when paying the [Call Cost] of "Topfist Vainglory, Brawlzeus" by using [Soulguard]?

A: Yes, they can. It is the owner of the card that decides whether or not to use [Soulguard] to keep the card in play.

Q2324: Can I put a card into the Drop Zone with the [Call Cost] of "Topfist Vainglory, Brawlzeus" if the card has an ability that prevents its own destruction?

A: Yes, you can.

Q2325: Can I put the opponent's "∞ Infinity the Chaos ∞" into the Drop Zone with the [Call Cost] of "Topfist Vainglory, Brawlzeus"?

A: No, you cannot. While "∞ Infinity the Chaos ∞" is a card on the field thanks to its ability, it also cannot be removed from the Flag Area thanks to another ability. You cannot pay the [Call Cost] of "Topfist Vainglory, Brawlzeus" using a card that cannot be put into the Drop Zone.

Q2326: Is it possible for my opponent to destroy the cards I wish to the send to the Drop Zone due to the [Call Cost] of "Topfist Vainglory, Brawlzeus" so that I cannot pay the [Call Cost]?

A: No, they cannot. It is only after paying all costs that the other player can [Counter]. No player can respond to a cost payment.

Q2327: When my opponent has 1 Life, I pay the [Call Cost] of "Topfist Vainglory, Brawlzeus". Can my opponent respond with a [Counter] to gain life?

A: No, they cannot. It is only after paying all costs that the other player can [Counter]. No player can respond to a cost payment. In this case, during the next Rules Resolution Step, which happens immediately following the declaration of the Call, your opponent loses the game due to having 0 Life.

Q2433: When there is an «Electrodeity» in the soul of "Electrodeity of Beauty, Ame-no-wakahiko", can it be put into the drop zone by "Topfist Vainglory, Brawlzeus"?

A: Yes, it can. [Call Cost] is not the effect of a card, so it can be put into the drop zone.