Frostwalk Bastion

{t}: Add {c}
{1}{s}: Until end of turn, Frostwalk Bastion becomes a 2/3 Construct artifact creature. It's still a land.
Whenever Frostwalk Bastion deals combat damage to a creature, tap that creature and it doesn’t untap during its controller’s next untap step.
{1}: Until your next turn, Forstwalk Bastion becomes a copy of target creature with a counter on it, except it’s 7/5 and it has this ability.