Demetria, Font of Harmony

Convoke
Defender, Vigilance, Trample
Whenever you tap a creature for mana or to help
pay for a spell with convoke, you gain 1 life.
{g/w}{g/w}{g/w}: Until end of turn, Demetria, Font of Life
can attack as though it didn't have defender. You
can only spend mana from creatures to activate
this ability.