Thanks to the Dark Irregulars' ample Soul Charging, by the time you need to use this Unit's effect, it is likely that you will have gotten a Werwolf Sieger in the Soul even without Riding one.
Rather than using this effect twice in one turn, it is better to use it in different turns. This will put more total pressure on the opponent, and is best when you are forced to draw out your opponent's Perfect Guards.
A good reason to use this card in a Dark Irregulars deck is to use this card to gain additional Grade 2 Units in your hand in order to reduce the risk of misriding, or to get more Shield and/or stronger Units.
This card, along with Gwynn the Ripper, are cost-efficient methods of using up your damage, if you are in a situation where you can't or don't want to use the effects of your other Grade 3 Units.
A good starting vanguard to facilitate this card's counter blast is Greedy Hand. Using his counterblast, you can soulcharge Werwolf Sieger from the deck, allowing you to meet the condition for the counterblast.