Ayucania Plains

Ayucania Plains enters the battlefield tapped.
{t}: Add {w} to your mana pool.
Tap a Human you control, {t}:
Creatures you control get +0/+2 {x} times until the end of the turn, {x} being the number of Ayucania Plains under your control divided by 2. Activate this ability only if an opponent declared attackers against you this turn.
The ayucanians trust on Cha-Iff, she retributes with protection.