歩行バリスタ
アーティファクト・クリーチャー — 構築物
歩行バリスタは、＋１/＋１カウンターがＸ個置かれた状態で戦場に出る。
：歩行バリスタの上に＋１/＋１カウンターを１個置く。
歩行バリスタの上から＋１/＋１カウンターを１個取り除く：クリーチャー１体かプレインズウォーカー１体かプレイヤー１人を対象とする。歩行バリスタはそれに１点のダメージを与える。
イラスト：
Double Masters#306レア日本語適正
裁定
A casting cost of means that you pay twice X. If you want X to be 3, you pay 
to cast Walking Ballista.
If Walking Ballista has been dealt damage or had its toughness reduced by an effect, this limits how many times you'll be able to remove +1/+1 counters from it in a single turn. For example, if it has three +1/+1 counters on it and has been dealt 1 damage this turn, it will be destroyed immediately after you activate the ability a second time and you won't be able to activate it a third time.
A casting cost of means that you pay twice X. If you want X to be 3, you pay to cast Walking Ballista.
If Walking Ballista has been dealt damage or had its toughness reduced by an effect, this limits how many times you'll be able to remove +1/+1 counters from it in a single turn. For example, if it has three +1/+1 counters on it and has been dealt 1 damage this turn, it will be destroyed immediately after you activate the ability a second time and you won't be able to activate it a third time.