Reach Beyond the Grave

Action - Destroy this: Return an ally card from your graveyard to your hand, then discard a card. Go again

Battleworn

Rulings

From the Compendium of Rathe release notes

When Reach Beyond the Grave’s activated ability resolves, you will choose and return an ally card from your graveyard to your hand, then you will choose and discard a card.
If no ally cards are available to return from your graveyard to your hand when this resolves, you will still discard a card.
When resolving Reach Beyond the Grave’s activated ability, there is no priority between any of the effects generated (e.g. returning an ally card, discarding a card).

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.