Shvult'Karth, Ironwinds

First Strike, Vigilance
Rain of Rust- Whenever Shvult'Karth
Ironwinds attacks. You may pay {b/g}{b/g}.
If you do. Target artifact gets a rust
counter on it. If it has five. Sacrifice it.
Ironwinds- Shvult'Karth, Ironwinds gets
a +1/+1 counter for each artifact card in each
player's graveyard.