Onnila under Siege

Whenever a creature deals combat damage, put a
flame counter onto this land. Then, if there are
three or more flame counters on it, sacrifice it.
Attacking creatures get +1/+0 for each flame
counter onto this land as long as it is tapped.
Blocking creatures get +0/+1 for each flame
counter onto this land as long as it is untapped.
{t}, Remove all flame counters from this land:
You lose that much life, then add {c}.