This helmet has three charges, which recharge at dawn.
By spending one charge, you attempt to beguile a dragon-type that you can see within 100-foot range. It must succeed on a DC 20 Wisdom saving throw, with disadvantage, or be charmed by you for you as long as you are attuned to the helmet.
While the creature is charmed, you have a telepathic link with it as long as the two of you are on the same plane of existence. You can use this telepathic link to issue commands to the creature while you are conscious (no action required), which it does its best to obey. You can specify a simple and general course of action, such as “Attack that creature,” “Run over there,” or “Fetch that object.” If the creature completes the order and doesn’t receive further direction from you, it defends and preserves itself to the best of its ability.
Destroying the helmet, or disenchanting it, will remove the ability forthright.
If you end up spending all three of the helmet’s charges, roll a 1d6. On a 1-5, nothing happens and you must wait for it to recharge. On a 6, the helmet rusts over and loses it’s enchantment, becoming useless.