Trinisphere Aetherdrift Return Toralf's Hammer to its

Return Toralf's Hammer to its owner's hand

or Dragon creature card from your hand onto the battlefield tapped and attacking that opponent

if the amount of mana spent to cast it was less than its mana value

then you may cast any number of spells from among those cards without paying their mana costs

Trinisphere Aetherdrift Return Toralf's Hammer to itsAs long as this artifact is untapped, each spell that would cost less than three mana to cast costs three mana to cast. (Additional mana in the cost may be paid with any color of mana or colorless mana. For example, a spell that would cost {1}{B} to cast costs {2}{B} to cast instead.)