[CONT] (V): If the number of <<Dark Irregulars>> in your soul is 15 or more, This unit gets (Critical)+2
[AUTO]: When this unit is placed on (V), choose one of your <<Dark Irregulars>> rear-guards, search your deck for up to three cards with the same name as that card, put them into your soul, and shuffle your deck.
That was a massive jump, strait from Booster Set 1 all the way to Booster Set 7 and not for a unit with Limit Break. Of the Dark Irregulars this is my favourite Grade 3 choice from the clan. He takes a lot of setup but with the correct support you can build up that set up rather quickly. Even using an unfinished deck made mostly from scraps, I've managed 12 soul by turn 4, getting me close to the activation point. Usually you're looking to Limit Break or Break Ride on turn 4-5 so this works out if you were going first, with the proper support I'd see no reason you couldn't make 15 Soul by turn 3, the trade off, or catch, being that turn 2 requires you make a full field rush with Decedent Succubus as your Vanguard, this however does leave you open and isn't advisable against decks that can hit hard and high early on.
What I really like about Reijy is the pressure he places on break ride dependant gambits, because your opponent can not afford to take a hit from him regardless if their Damage is 2 or 3, because do they really want to chance you checking a critical trigger on an already 3 Crit Vanguard? Probably not. If using the Break Ride, King Of Masks, Dantarian. As each of your booster could become Demon World Marquis, Amon for the duration of that turn.
Image it, Amon on 3 Critcal before attack, seems threatening doesn't it? DON'T DO IT UNLESS YOU HAVE TO! Reijy will already have (Power)+10000 from a Break Ride, even with a 5k booster, he'll be hitting for 26000, which will be Sentinel'd anyway. Instead, with the 15 Soul you have, try and give one of your Rear-Guard Colums +15000*2(=+30000)
Even without a Break Ride, the Demon Bike and Demon Chariots make for excellent Reijy Support gaining power each copy of them there is in the soul, and Reijy can seach out those copies with his second skill, this was infact how he was intended to be used, as evidenced by his second skill. You could also call a Dimension Creeper so you can then search out the other three to instantly +6 Soul. Grade 0-2 is 3 cards itself so +6=9 Soul say you used Greedy Hand (which I would advice when using Reijy) that's 10. But really, as tempting as it may be to fill your soul with Dimension Creepers using Reijy's skill, it not the thing to do. Use the Chariot series, search any still in deck copies with Reijy, for getting Dimension Creeper's into the Soul, use Greedy Hand and a unit called Free Traveler. Both of which have the skill of Searching out a "Grade 1 or Less <<Dark Irregulars>>" and adding it to your soul.
The reason why Reijy is the Card Of The Week, but I'm spening most of the article discussing his support is because as good as I think he is, as much as I like the unit and what it can do, what it can do is exactly the very problem with this unit. Blade Wing Reijy is a Grade 3 gambit that by itself is useless, he os however the perfect example of of how the correct support can make all the difference between victory or defeat. Which aince, you'll be heavily Soul Charging, see if you can make room for the Grade 1 and Grade 2 Amon's while you're at it, along wit Doreen The Thruster. That's said you don't need the Amon's AND the Chariots, so in that case choose one or the other, but I heavily reccomend Doreen.
EDIT has been made having realised a massive and blatant mistake I shouldn't have made in the first place. Apoligies.