Mardu Warshrieker

Creature — Orc Shaman

Raid — When Mardu Warshrieker enters the battlefield, if you attacked this turn, add .

3/3

2014-09-20:
Mardu Warshrieker’s raid ability isn’t a mana ability even though it adds mana to your mana pool. It uses the stack and can be responded to.
2018-01-19:
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.
2018-01-19:
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.