Dark armed dragon effect..?

Question

when dark armed dragon is summoned,how many times can he use its effect in one turn..

Answer 1

Dark Armed Dragon effect that destroys 1 card is an Ignition Effect. Removing 1 DARK monster from play is a cost.

That means you can use it more than once.

Answer 2

He can use his effect equal to the number of dark monsters in your graveyard.

Answer 3

as many times as you want. it doesn't say anything like "you can only use this effect once per turn" or "once per turn..."