As a safe swift action, add 2 damage to your weapons.
As you establish/maintain a pin, deal 1d4 CON damage and heal 5 HP.
As a safe standard action,
summon 1d6+1 rat swarms,
1d4+1 bat swarms,
or 2d6 wolves.
They arrive in 2d6 rounds and stay for 1 hour.
Creatures slain by Blood Drain or negative levels become spawns.