Dragonscaler Flight Path

Instant -

, destroy this: Target Draconic attack gets go again. If it's a weapon or ally attack, you may attack with it an additional time this turn. This ability costs

less to activate for each Draconic chain link you control.

Battleworn

Rulings

From the The Hunted release notes

If the combat chain is open, you are still considered to control a (Draconic) chain link, even if the attack is no longer on the combat chain. Last Known Information is used to determine the type of a chain link.
Decreases to resource costs are applied after increases to resource costs. If an effect would increase the resource cost of activating Draconscaler Flight Path, the decreases would be applied last.
When you activate Dragonscaler Flight Path’s ability, you must target a Draconic attack, which may be typically an attack from a Draconic weapon, Draconic ally, or Draconic attack action card. The targeted Draconic attack may be one controlled by another hero, in which case the cost to activate it is not reduced by Dragonscaler Flight Path’s own cost decrease effect (you don’t control chain links on other heroes’ turns).
When Dragonscaler Flight Path’s activated ability resolves, the targeted Draconic attack gets go again. If it was a weapon attack or ally attack, that weapon/ally may attack an additional time this turn. This is provided you are able to successfully activate their attack abilities again (i.e. pay any required action points, pay resource point costs, etc.).
Effects that allow the additional activation of an activated ability are additive e.g. if you have two separate effects that both allow you to attack with a weapon an additional time, you will be able to activate the attack ability 2 additional times.

Keyword notes

Battleworn - Equipment that wear down after each time they are used to defend. If you defend with a card with Battleworn, put a -1{d} counter on it when the combat chain closes.

When you defend with a card it remains on the combat chain until the chain closes, therefore you cannot defend with an equipment multiple times on the same combat chain.
A -1 counter stays on the card until the card is destroyed or the game ends.
If the defense of a card that is defending is below zero, its defense value is considered to be zero.
When this card is destroyed, it is sent to your graveyard. (Not when it has 0)
When this card is destroyed, it is sent to your graveyard.
If the defense of a card that is defending is below zero, calculate as if its defense is zero.