It’s a difficult assist to wrap your head around using. Basically, there are two main uses of Daggers.
The first main use is the same thing Strange gets out of the move on point: teleport mixups. If you have a grounded teleport character you can make use of this assist. It might make sense at first to use Bolts for this, but because it’s duckable, and teleports have recovery, this isn’t safe. Daggers are guaranteed to hit as soon as Strange recovers from the assist. The assist version of Daggers actually recovers slightly faster than the point version, so this is a plus.
Basically, call the assist while you have your opponent in blockstun (or before, depending on the timing you need,) and left/right them with the assist.
THE BIGGEST ISSUE WITH THIS is that the nature of Daggers makes it easily avoidable by anyone who has free movement options (i.e. not in blockstun.) All the opponent has to do is travel in a direction perpendicular to the line between the daggers and them when they fire. The closer they are to the daggers, the harder this is for them to do, so Daggers are always more effective at closer ranges.
This fact can be abused however for main use number two. I play Zero with Daggers against other Zero’s that don’t have particularly scary assists Zero can’t deal with on his own. In that mirror match, the opposing Zero has to be weary of Daggers at any position on the screen, and once they fire, they must block or get out of the way. Either way, you get an advantage. If they block, well they block, go in. If they want to avoid the Daggers, their escape vector will almost always be predictable. If they’re on the ground, they’ll jump or super jump. If they’re in the air, they’ll teleport down. If they’re too close to the Daggers, they’ll probably just block it. Because you are in this situation where you know what your opponent will do, you can abuse this and intercept their escape route with a punish or mixup. Against any character with high mobility, this is the best use you’ll get out of Daggers, but it also plays double duty as a mixup tool for teleporters.
Even if your characters can’t fully exploit these strategies, Daggers on their own is just an annoying assist to deal with. It totals with 9 points of durability, so it’s even tough to beat out. As long as you can protect Strange while he casts it, you got a big advantage. That’s the biggest strength of the assist, the “you must deal with this” factor. The worst part about this assist though is that it doesn’t do a lot of hitstun, which kind of sucks. Also, the projectiles appear in a random pattern, so combos using this assist can sometimes be unpredictable.
It’s a great and underused assist though. It shines in specific matchups over Strange’s other assist choices, which are admittedly more applicable, but no assist in the game is as unique as Daggers of Denak. Use it.
DoD >Mag assist > teleport.