Overview
They actually added a knife gun to the game. Pictures of this thing just scream bad idea.
QSB-91 is another DPS HG, which in of itself is a pretty niche archetype that does not always see much use. Her active skill is a nuke, making her similar to the likes of CZ75. However, QSB-91 actually has an even stronger nuke than her 5-star semi-counterpart, just split over 4 separate attacks. Combined with her strong tiles and passive that enables her to shred through enemies like Orthrus and scouts, and she is… still not a very good option.
While she brings some extra utility that CZ75 does not, QSB-91 is simply not as good as a regular DPS buffing HG like Mk23 most of the time, and a poor budget option since she is a monthly login reward.
Pros
Good FP Tilebuff
QSB-91 has her pure FP buff of 32%, which helps any DPS units deal with enemies she can’t.
Excellent Tile Coverage
From the frontline QSB-91 can reach both sides and behind her.
Early Initial Cooldown Nuke
QSB-91’s first nuke on her skill starts at 4 seconds, which is earlier than other HG nukes.
Cons
RNG Targetting
What QSB-91’s skill specifically nukes is randomly selected.
No Skill Buff
QSB-91’s role in a team is potentially better replaced by a generalist buffing HG that improves the backline’s DPS.
Insufficient Damage For High End Content
QSB-91’s nuke, while strong for a HG, can fall off against very tanky enemies in high end content.
Monthly Reward Doll
As a monthly reward doll, QSB-91 is not a good budget unit as dupes of her cannot be farmed/ are difficult to farm for links.
Full analysis
Her passive attacks close enemies 4 times in a row ignoring evasion each time she attacks. This means she can deal well with Evasion-focused melee-range enemies such as scouts and enemies that only take 1 damage like Orthrus, while sacrificing any significant damage to armored enemies.
Her active skill comes out very early at 4 seconds, and the overall damage from all 4 attacks is higher than the 5* bamboo HG CZ75, totaling 24x to her 10x, and even starting earlier, taking from 4-8 seconds to fully realize all the damage. It even ignores HP shields, which helps if you want to kill a strider with a freaking HG I suppose.
Her damage output compared to major self-buffing HGs like Python and DEagle is usually lower, making her weaker when killing bosses and the like.
Her tiles and passive skill want her to stand at the front of the echelon to get the greatest effect, but that is where the damage comes from. QSB-91 has no survivability skills and average survivability stats for a HG, which is like paper compared to SMGs and SGs. Also her DPS is reliant on her links, so this positioning is actually counterproductive for her. Even against Orthrus, which she should specialize in, that should not usually be attacking her will still bite her when the shield goes down, and often come with escorts that will shoot her full of holes.
Conclusion is, don’t use this HG, unless you’re doing some kind of bizarre meme. Her own specializations and unique skill set that beats out her own higher rarity counterparts are overshadowed by regular HGs and her counterproductive kit.