Ruin Raider

Oracle Text

Raid — At the beginning of your end step, if you attacked with a creature this turn, reveal the top card of your library and put that card into your hand. You lose life equal to the card's converted mana cost.

Card Rulings

9/29/2017 If the mana cost of the revealed card includes , X is considered to be 0.
9/29/2017 If the revealed card doesn’t have a mana cost (because it’s a land card, for example), its converted mana cost is 0.
9/29/2017 The converted mana cost of a split card, such as cards with aftermath from the Amonkhet block, is based on the combined mana cost of its two halves.
1/19/2018 Raid abilities care only that you attacked with a creature. It doesn’t matter how many creatures you attacked with, or which opponent or planeswalker controlled by an opponent those creatures attacked.
1/19/2018 Raid abilities evaluate the entire turn to see if you attacked with a creature. That creature doesn’t have to still be on the battlefield. Similarly, the player or planeswalker it attacked doesn’t have to still be in the game or on the battlefield, respectively.
1/19/2018 Some raid abilities trigger at the beginning of your end step. These abilities trigger if you attacked with a creature that turn, even if the card with that raid ability wasn’t on the battlefield when you attacked.