Usually I see people use the shield for the insane speed boost. Occasionally if I'm dropping Vortex Bombs, a guy will lay down a firestorm on top of everything.

I use my buddy Dr-Drakon. I leave a normal harness on him and whenever I bring a poor loadout to a danger room I especially make use of sprite abilities to compensate.

Otherwise I'll usually use Concussive Firebolt to hit switches, to initiate on enemies, stun part of a crowd.
If there are greavers, I'll use my Explosive Firestorm to give some breathing room and I'll hopefully kill them if I don't have terrible weapons with me.
I rarely use Scorching Barrier because it's the most dangerous option to legitimately use. I basically only use it if I'm support bombing to supplement my lack of damage.

Recently I've been doing this combo: Obsidian Crusher >> Ionized Salt Bomb >> Firebolt >> Tortoshield bash. You can fit that all in before the OC explodes IFF you have a decent crowd of enemies that don't disperse on a Tortoshield bash. I used the bomb CTR med perk, but you could probably do without. That's potentially 4 statuses with all normal or shadow damage. However, it's not exactly useful on Jellies because a DR would be a much easier and better option.
Sadly, you can't translate this beautiful combo to other damage types... the weapons aren't there to support it.

It's a good sprite for pure bombers, offering a direct attaack, a means of manipulating far off switches, protection, mobility (or even more damage!), and added damage for vortexes.

Scorching Barrier + Rocket Hammer is still my favorite combination in the game, and I use it whenever I do Legion of Almire. It promotes such a fun, hyper-aggressive playstyle.

2 years or so since sprites release and I'm still really bad at consistently making use of my sprites. I do use Drakon a bit but it's mostly when I wanna go fast.

My Drakon is the only sprite I have at the moment, and I use it all the time. In fact, I use his Firebolt ability so often that I start pressing one when I'm facing monsters in other games XD

Is the explosive firestorm good?

I got frenzied on my ones and I rarely play with winged drakon owners, so I can't rly tell. But imo the dmg/asi boost and the chance for flashcharging is better, since YOU can do more dmg, not the sprite. This 'upgrades' it to a good party friendly sprite (sera is alrdy built for that, the mask's quills helps everyone). It also makes it viable on fire themed areas, since for the boost the enemies don't have to be set ablaze, just be in the firestorm.

Scorching Fire Barrier + DVS is still my favorite combo of all time. Throw in another barrier for extra sizzle. (Shock Barrier works best.)

The explosive firestorm is also viable on fire-themed areas, it basically deals damage+fire, so in fire-themed areas it will still deal damage. It's over 50 damage per hit and it hits a lot of times. Frenzied is probably better, though, especially in a party. I say probably because in some situations, getting the boost is not that useful if you are under lots of pressure and unable to set up a flash charge anyway, then it's better to have an instant-use AoE bomb (I guess it's probably closest to compare it to dark retribution, fast and small hits + fire status) to soften up the enemies while staying safe yourself.

I think it's like 55 dmg with an elemental harness on Legion of Almire, it's been a long time since I played SK, I just came back so I don't remember everything. But I do remember it's a lot of 55's popping up, similar to DR or shock ticks on a crowd...