Mages' Contest [The List] Set_Worldbreaker {4}: Put a +1/+1 counter

{4}: Put a +1/+1 counter on Walking Ballista

Legendary Foe (Foil) - Kassen #LF3 | The Nerd Merchant

Set: Promo Finish: Cold Foil - Golden Type: Equipment Subtype: Head Rarity: Promo Class: Earth Once per Turn Instant - [1 Resource]

Set: EX: Dragon Frontiers Type: Fighting Rarity: Ultra Rare Retreat cost: Colorless

it also gains the following ability until end of turn

Mages' Contest [The List] Set_Worldbreaker {4}: Put a +1/+1 counterSet: The List Type: Instant Rarity: Rare Cost: {1}{R}{R} You and target spell's controller bid life. You start the bidding with a bid of 1. In turn order, each player may top the high bid. The bidding ends if the high bid stands. The high bidder loses life equal to the high bid. If you win the bidding, counter that spell.