Ardent Hero

From Archon Arcana
Ardent Hero • Sanctum • Creature • Common • Taunt. (This creature’s neighbors cannot be attacked unless they have taunt.)

Ardent Hero cannot be dealt damage by Mutant creatures or creatures with power 5 or higher. • Artist: Radial Studio • Card Number: MM (126)

Ardent Hero
Taunt. (This creature’s neighbors cannot be attacked unless they have taunt.)

Ardent Hero cannot be dealt damage by Mutant creatures or creatures with power 5 or higher.

MM 126

FFG Rulings

  • No. Because Rock Hurling Giant has 6 power, it cannot deal damage to Ardent Hero from its power or from its printed abilities. In general, the source of damage is the card that is dealing that damage, with the exception of damage bonus icons, because that damage is done by a game step.

    Source: Rulebook
Can Rock-Hurling Giant’s (CotA 44) ability deal damage to Ardent Hero (MM 126)?
No. Because Rock Hurling Giant has 6 power, it cannot deal damage to Ardent Hero from its power or from its printed abilities. In general, the source of damage is the card that is dealing that damage, with the exception of damage bonus icons, because that damage is done by a game step.

Source: Rulebook

Commentary

Effects may still attempt to deal damage to a creature that "cannot be dealt damage", but the targeted creature's ability will prevent that damage according to the first step of the Damage section of the Timing Chart.

Source: Timing Chart