Tl;dr : The flame staff is too specialized in pure Horde-clearing, when the game is chock-full of gunners. I would argue it’s not even the best at doing that because the Voidstrike staff also exists.
I’m an adept of the Surge staff and the Voidstrike staff. And I think we can agree that they are pretty good in QuickPlay, even in the higher difficulties.
But I’ve been trying to use the Flame staff on Malice for a while now, and I am of the opinion that, while it can be used effectively on difficulties 3 and below (especially with a pre-made group), it is definitely bottom tier, just like Sienna’s flamestorm staff in VT2.
Let’s go over why :
Lack of ranged option besides BrainBurst. While the staff is quick to equip compared to the Preacher’s flamer, it doesn’t reach very far. Being forced to resort to BrainBurst to help kill gunners feels really slow. The Surge staff has much better range, and can be used while peeking behind cover. The Voidstrike M2 is a big, fast projectile with no falloff.
Mediocre stagger power. Not very effective on mixed hordes. The M2 does not have enough stagger power to stop Ragers, even on Diff2, but the M1 can. It has very bad damage, however.
The low mobility of the Mouse2 flamethrower. While you can dodge some while casting, it also has blind spots up close which makes it risky to use if nobody is closely watching your back.
Mediocre Damage Over Time. The number of stacks required for something to die by DOT in about 5 seconds is incredibly high even in Diff3 and requires either spamming M1 for quite some time or sacrificing all mobility to use the M2. I have also compared two staves with very different values for the ‘Burn’ stat. It makes no difference whatsoever.
No visibility. The little cloud the M1 produces does not obscure your visibility, but the M2 flamethrower… You can’t see anything while using it. I don’t much care about realism. I would very much like be able to see whether or not my targets have been staggered or have died, so I can stop channeling the flamethrower and stop being a sitting duck.
In short : this is a staff with little versatility that makes you very reliant on your teammates to do what you cannot, which is everything except horde-clear. The risk-reward also seems skewed compared to other staves.
The Voidstrike staff also has some mobility issues with its M2, but has almost the same horde killing potential while also being capable of long-range sniping and support.
The Surge staff is not without its weakness. It is weak, but it is very support-oriented, has a lot of utility, does not require good aim but sometimes does not strike the targets you want it to. It has decent range (provided the enemy is not below you). It is not strong against hordes, but a good horde-clearing weapon can help with that.
Objectively, I think there are very few reasons to use the Flame Staff over these other options. It has some talent synergy with Ascending Blaze, but the DOT isn’t very good unless you spend all 6 Warp Charges, and you are not likely to get them back unless many minions die from the DOT. It is debatable whether it’s worth sacrificing the other talents to make Ascending Blaze work.
Lower the opacity of the fire cloud effects, please. That’s a no-brainer.
Give it some more range (maybe something closer to the Preacher’s flamer)
Or change the M1 to a long-range projectile of some sort
The M2 flamethrower could use a little more damage and/or stagger. It’s very much inferior to the Preacher’s flamer in both respects. Although it does not require ammunition or reloading, it does require charging and Peril, that should count for something.