(Dragonskull of the Burnwillows isn't a spell.)
At the beginning of your end step, if you didn't cast any spells this turn, Dragonskull of the Burnwillows deals 1 damage to you.
Attacking creatures you control get +1/+0.
: Add 
to your mana pool. Dragonskull of the Burnwillows doesn't untap during your next untap step.