This relic benefits during turns where you need to use all Energy to block fully in order to negate a large amount of damage. This relic is also useful during turn 1 on characters like the Defect and the Silent, as a good number of decks for the aforementioned characters include a turn 1 where only powers or skills are played.
Synergy
Pocketwatch: On turns where Pocketwatch activates, there is a good chance you did not play any attacks. This allows you to benefit more from the additional energy next turn, as you will have more cards to work with due to Pocketwatch.
Snecko Eye: On turns where Art of War activates, the additional energy will allow you to play more cards if Snecko Eye randomizes cards into mostly high costs.
Letter Opener: Allows you to deal damage without playing attack.
The Bomb: The Bomb is a skill which deals damage, meaning you can deal damage without losing the benefit of Art of War.
All attack cards: Prevents Art of War from triggering.
Double Tap: Playing this skill would be a waste of Energy unless you played an attack, therefore preventing Art of War from triggering.
Pocketwatch: On turns where 
Snecko Eye: On turns where Art of War activates, the additional energy will allow you to play more cards if 
