Rusted Guardian

Rusted Guardian enters the battlefield with 4 -1/-1 counters on it. As long as Rusted Guardian has a -1/-1 counter on it, it has defender.
{1}: Remove a -1/-1 counter from Rusted Guardian.
The Xerxians once built great constructs to defend their cities. Now, their cities are in ruins, and their constructs have fallen into disrepair.