Better than what looks like at first sight. As said by roach8700, its better used at Heroes that have triple resources, like Captain Marvel, Hulk, maybe Domino. But Bishop could also get use of it since its a resource card based hero and you will have more turns than other heroes, with avaiable resources on hand or to be fished back.

Aside from the flexibility that it can give to a well coordinated team, sharing the same aspect we have a good combo with Beast: use the stored resource to pay him and immediatly return it back to your hand. And for characters with multiaspects we have by example Spider-Woman with Pool's triple resources to share (note to mention for comparison: Plot Convenience is of higher cost but can store up to three of any aspect card, plus others can store their cards there too)

The real value of the card (especially in Solo) is to be able to save a resource for later turns yet liberating the hand slot. Once you use one store res, it will yield a decent -1ER for the trick. Once you use two or more times the store resource, it will pay itself.

Its also worth to note that decks with heavy costs like a Dum Dum Dugan based deck or (as ZaneBrick said) Maria Hill's arkships will also love to accumulate extra resources for burst paying these expensiveties. A blue aspect is based mostly on helping the team and Resource Reserve fits that role, just in the cost management

Multiplayer Review

My current deck building focus is Repurpose and this card works as a great consistent combo extender for the stat boost from Repurpose. I had initially written this card off as a Drax only card due to his 6ATK potential but running this in a 2-4 player game with both a Drax and Rocket Repurpose player can greatly increase the amount of turns that this readying effect becomes resource efficient (2 resources for 6 damage or 2 resources for 5-11 damage/thwart depending on how many Repurpose you can play in a turn).

There are a couple more applications that past reviews and my own comments had overlooked. Specifically 2 allies: Spider UK (web warriors) and Groot (Guardian heroes only). When paired with Energy Shield both can become semi-permanent blockers against villain attacks, especially Groot.

This card’s consistency has been greatly improved with the addition of Energy Shield. Now Guardian heroes can run the Groot ally and Victor Mancha and maintain them both as semi-permanent blockers. This card will still be much more playable in multi-player and depending on the villain can dish out crazy damage. When evaluating damage mitigation I think it’s best to think of it as delayed threat mitigation. If you don’t get low you don’t have to flip down. If you don’t flip down the villain won’t scheme.

I use to include him in my Nightcrawler deck, along with Hangar Bay to stall two 1ATK minions, which slows the pressure for a team that still needs to build up or focus other things before dealing with minions. And NC deals with the villain, covering both types of most common damaging menaces. The said deck was on a team of three who also included Honorary X-Men to allow the X-Mansion to heal him when no other important character is wounded. That makes him cappable of walling a 2-Atk minion for 4+ turns, and also raises his HP to 5 which can result into even surviving a villain's attack. Ops Room can help him soak 2-ATK minions and reward you with threat removal for three turns at 6ER total.