Sworn in Undeath

Vigilance.
Undying(When this creature dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)
If you've cast a white spell this turn, remove all +1/+1 from Sworn in Undeath at the end of turn.
The city was destroyed and the castle had crumbled long ago, but the paladin kept his post.