Sorania, The Mana Monger

Leyline(Each untapped land you don't control you
tap while casting this spell pays for {1}.)
If you would lose unspent mana, that mana
becomes green instead.
Whenever an opponent would tap a nonbasic
land for mana, add {g}.
{r}{g}{g}{g}{g},{t}:Put four +1/+1 counters on
target creature.