The mana value of a modal double-faced card is based on the characteristics of the face that's being considered. On the stack and battlefield, consider whichever face is up. In all other zones, consider only the front face. This is different than how the mana value of a transforming double-faced card is determined.
Toralf, God of Fury // Toralf's Hammer
The creature equipped by Toralf's Hammer is the source of the activated ability, but Toralf's Hammer is the source of the damage. For example, if the equipped creature is green, that ability can't target a permanent with protection from green. It could target one with protection from red, though the damage would be prevented as it would have been dealt by a red source (Toralf's Hammer).
A creature has been dealt excess damage if one or more sources deal more damage to it than the minimum amount of damage required to be lethal damage. In most cases, this means damage greater than its toughness, but consider any damage already dealt to it that turn.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Matt Stikker
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
