However, the international release of VGE-BT14: Brilliant Strike last Thursday has serious consequences for both entry-level play and professional Vanguard, marking the formal introduction of Quintet Wall to the rest of the world. Quintet Walls are new variation of cards bearing Sentinel, which previously belonged exclusively to perfect defense cards; the basic characteristics are that these cards have a shield of 0 and the Sentinel skill, which states that only up to four cards with Sentinel may be included in a deck. The actual skill of Quintet Wall cards is to counterblast 1 and superior call five cards from the top of the deck to guard with, potentially giving vast amounts of shield to work with that do not come from the hand. After playing a Quintet one is still free to call additional cards from the hand, opening up an alternative defensive option on par with perfect defense.
Having preordered in the range of half the price of the cheaper perfect defenses, some of these Quintets like Sword Formation Liberator Igraine have sold for as low as $4, in this example compared to her perfect defense counterpart's $13. These prices have developed in light the poor reception of the mechanic by more competitively-minded cardfighters, and because of these cards' perceived lack of use prior to the introduction of Legion. Halving the cost of effective deckbuilding encourages cardfighters to try out different clans, and makes it easier on entry-level fighters to learn different play styles without having to dedicate financially to a clan they aren't certain of. In this way Cardfight!! Vanguard is becoming cheaper to play. For entry-level players Quintet Walls are an efficient means to get into playing a clan without paying the exorbitant "entry fee" of assembling four perfect defense cards. This is not a perfect substitution; as outlined below, if Quintets are to be used at all then they are best used in careful combination with perfect defense, not as a total replacement. They're also dangerous when overused. So for beginning players running just three Quintets can be serviceable, both to prevent abuse and help with not over dedicating to the mechanic, leaving them prepared to eventually transition towards perfect defenses once this becomes financially practical. Having inferior but more strategically complete decks helps new fighters top more consistently at their card shops, accumulate store credit over time and eventually be able to afford the "completed" versions of their decks.
Outlining their characteristics as a whole, because a Quintet Wall only activates from the hand you cannot activate a Quintet called by a Quintet, but perfect defense cards called in this way will be usable because they trigger when placed on the guardian circle regardless of where they originate from. Since Quintet Walls and perfect defense cards share the Sentinel skill this interaction normally only compensates for not running a perfect defense instead of a Quintet in the first place. However, there are specific matchups that Quintet Walls shine in. Versus Dragonic Nouvelle Vague they make more efficient use of grade 0 units, as DNV only blocks grade 0s called from the hand not the deck, and those grade 0s are better off in the guardian circle than in your hand. You do run the risk of eliminating positive drive checks for next turn in this way. It can be argued that you could have used a perfect defense versus DNV to similar effect, but that would cost you another card from the hand which may be more difficult to front compared to a single counterblast. We can make a more general observation from this that using Quintet Walls has a side effect of conserving hand advantage over time, although this is not perfectly true as there will be cases where you need to patch up your defense with additional cards from the hand.
Quintet Walls also directly counter the Daikaiser break ride skill, which has been a menace in both the Japanese and English-language formats. Since Daikaiser can only retire one card per grade 3 drive check on the turn of his break ride, Quintet Walls are useful for dividing up the shield between units called from the deck. Let's consider an extreme example; 40000 shield divided among three 10000-shield units and two 5000-units. If Daikaiser attacks boosted for 30000 power after break riding itself versus a current defense of 51000 power, even two grade 3 checks will only bring the total shield down to 31000 power, just enough to block the attack. The remaining rearguard attacks are much easier to guard and the hand as a whole is preserved because the bulk of the turn's defense is split among a large amount of resources that you yourself do not have to front from your own hand. Quintet Walls are also optimal to stop early and midgame aggression, as they aren't as expensive in terms of cost as perfect defenses and so can be used more freely earlier in the fight. However, they have specific weaknesses versus high-power center lanes that can consistently demand excessive amounts of shield. Versus Tryannolegend, Labrador and Ezel Scissors, each of whom can consistently make a 31~41000 power 2 critical lane, perfect defenses are vastly preferable. The key to using Quintets effectively is to balance them with perfect defense cards, so that your plays can be more flexible. A ratio of 3:1 perfect defense to Quintet or 2:2 is considered a good balance. Of course, Quintets are not right for every deck, so the old standby of 4:0 is still very viable. If you have the open counterblast demanded by them, they can be beneficial to try and take advantage of, but they are not a straight upgrade nor an absolute replacement over perfect defense cards. Be wary of how many cards Quintets remove from the deck as well--using just two of them removes one fifth of the deck, and using four of them will take out 20 cards in total. This can make decking out a very real possibility. The Legion format on the whole benefits much more from Quintets than limit break vanguards do, as the mechanics of that format allows for trigger units called by Quintets to be freely recycled back into the deck on the following turns.
Versus Dragonic Kaiser Vermillion and other cards that can attack multiple units simultaneously, the cards superior called by a Quintet Wall can also be individually allocated to guard separate units. For example, if an unboosted in-Legion Big Bang Knuckle Buster attacks for 25000 power against four units comprising the vanguard (11000 power) both frontrow rearguards (9000 power each) and a backrow booster (7000 power) and your Quintet calls out one perfect defense card and four 10000-shield units, you can discard to activate the perfect defense and protect the vanguard, then allocate 20000 shield each to one of your frontrow units and your booster. The third unit which is unprotected will be retired when the attack hits, but in order for Big Bang to hit the remaining rearguards it will have to drive check a trigger, which is not a bad deal when you consider that you've only fronted two cards from your hand to protect three of your four units. While the same amount of cards was spent from the hand as if the Quintet were just a perfect defense, being able to pull out additional shield protects the remaining rearguards and decreases the overall impact of Knuckle Buster's Legion skill, while still leaving room to put down additional cards as needed to secure the rearguards it attacked and be able to take on the opponent's remaining attacks for the turn.
By 2015 a total of fifteen clans are to have received one or more Quintet Walls; Summoning Jewel Knight Gloria for Royal Paladin, Hatred Prison Revenger Cessair and Barrier Witch Graine for Shadow Paladin, Sword Formation Liberator Igraine for Gold Paladin, Shield Goddess Aegis and Regalia of Frozen Breath Svalin for Genesis, Dragon Knight Gimel for Kagerou, Hardship Brawler Toshu for Narukami, Silver Snow Sasame for Murakumo, Machining Ladybug for Megacolony, Moth Orchid Musketeer Christie for Neo Nectar, Blue Storm Guardian Dragon Icefall Dragon for Aqua Force, Duo Promise Day Colima for Bermuda Triangle, Reef Banshee for Granblue, Baron Amadeus for Spike Brothers, Metalborg Bri Knuckle for Dimension Police and Shieldraizer for Nova Grappler. Those expected to benefit the most from the mechanic are Granblue and Neo Nectar, whose drop zone-centric strategies make the cards a welcome addition to their playbooks, while at least one Quintet Wall has been a standard staple to help Legion decks accelerate their gameplan. Despite having a number of counterblast 2 skills in their respective variations, Nova Grappler and Megacolony do stand to benefit from Quintets' advantage-conserving aspects, as these builds have a difficult time amassing card advantage and being forced to drop an early perfect defense can represent a major setback to their gameplan.