Taliyah the Stoneweaver

Haste, Reach
{t}: Tap X Mountains and deals X damages to
target creature or planeswalker, XX damages
if all Basic Lands you control are Mountains.
{t}: Tap X Mountains. X creatures you control
get "Inderstructible" and "this creature cannot
inflict damages" until the end of the turn.
Activate this ability as an instant.