Graven Cowl

While this is in your graveyard, at the start of your turn, you may destroy 2 Silver you control. If you do, equip this.

When this is equipped from anywhere other than your graveyard, put a -1

counter on it.

Blade Break

Rulings

From the Compendium of Rathe release notes

Graven Cowl’s first ability is functional while its in your graveyard and triggers at the start of your turn. This is an optional effect: you may choose to destroy 2 silver you control when the triggered effect resolves. If you do, you will equip it.
Neither player receives priority during the start phase of a turn.
Graven Cowl’s second ability triggers when it is equipped from anywhere other than your graveyard. This includes triggering at the start of the game. You will put a -1 counter on it when the triggered effect resolves.

Keyword notes

Bladebreak - Equipment that are fragile and break after being used to defend. If you defend with a card with Blade Break, destroy 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.
When this card is destroyed, it is sent to your graveyard.
The ability becomes a layer on the chain when the combat chain closes.
The Blade Break ability becomes a layer on the chain when the combat chain closes.
The ability goes on the stack when the combat chain closes.

All keywords

ClassAssassin

TypeEquipment

SubtypesHead

Defense2

KeywordsBlade Break

SetsPEN