AUTO: [Soulblast 2] When this unit is called to a rearguard circle you may pay the cost, if you do, countercharge 2.
Since Cardfight!! Vanguard's first booster set hit in March 2011, the game has included counterblast, soulblast, soulcharge and unflipping as part of its core resource mechanics. Of these, counterblast and unflipping are arguably the most definitive features of Vanguard's core gameplay that differentiate it from existing Trading Card Games, alongside drive checks.
Each player necessarily takes damage in order to get access to more powerful counterblast-dependent skills, and accordingly has to weigh the risk of going to a dangerous threshold like three or four damage more quickly in order to gain access to those game-determining skills sooner. However, unflipping damage has been the odd mechanic out in that it has no formal icons. Nina's publication changes this by rewriting "Choose up to 2 face-down cards in your Damage Zone and flip them face-up" as "countercharge 2."
Retroactively all instances of unflipping have become countercharge, a means of "filling up" the damage zone without taking damage. This is less intuitive than soulcharging because no cards are actually added to the damage zone and it can only restore what has already been used, but it does clarify for cardfighters one fact of resource management that has not always been completely clear. Nina is just one of many clones of Battle Sister Lemonade, a soulbast 2 unflipper in Oracle Think Tank, and the new wording more clearly explains that with all of these cards one is trading the soul resource for open damage. No less nor greater number of resources are gained than are put in, blasting one resource and charging another in an equal amount. While this has always been true, the new wording and icons associated with it make this fact more obvious, and in turn it's now easier to teach newcomers this core principle of gameplay.
