Spark Fiend [Unglued] Colorless [x2] It gains 400 ATK until

It gains 400 ATK until the End Phase

Much more than death

you can also Xyz Summon "Cyber Dragon Infinity" by using "Cyber Dragon Nova" you control as the Xyz Material

Set: Junior Super Series Type: Land Rarity: Rare Whenever City of Brass becomes tapped

Spark Fiend [Unglued] Colorless [x2] It gains 400 ATK untilSet: Unglued Type: Creature Beast Rarity: Rare Cost: {4}{R} When Spark Fiend enters the battlefield, roll two six sided dice. If you rolled 2, 3, or 12, sacrifice Spark Fiend. If you rolled 7 or 11, don't roll dice for Spark Fiend during any of your following upkeeps. If you rolled any other total, note that total. At the beginning of your upkeep, roll two six sided dice. If you rolled 7, sacrifice Spark Fiend. If you roll the noted total, don't roll