Evolution
Powder Kegs Description: Lobs explosive kegs that detonate in an area around the hero.
Haunted Fire Description: Kegs leave a lingering green fire cloud. Haunted Fire increases the cloud's duration.
Powder Kegs are the special weapon from the Black Tide event, and unlike the heroes, this one is genuinely gettable if you are new.
They cost 10,000 Skull Coins outright, or you can hit them on the wheel at 0.3% a spin. Realistically you net around 64 free spins over the event, which leaves 36 to buy at 200 gems each. Call it 7,200 gems.
That is on the expensive side for a weapon. I normally want to pay 3,000 or 4,000, which is roughly what the Mine Event charges, and this weapon will eventually show up there. So if you can wait, wait.
But if you are early in the game, do not wait. You pick up a real pile of gems just clearing normal and hard mode chapters in this event, so 7,000 gems is not the wall it sounds like, and Powder Kegs will carry you through content for a long time.
On the forge, tier one is Another! or Keg Hurl Expert. Take Another!, because you almost always want projectiles over projectile speed. Tier two is Bigger Boom for +20% area of effect or More Kegs for another projectile, and I go More Kegs for the same reason. Special Mix is the 3-star, and Haunted Fire is the evolution, which increases cloud duration.
The last tier is the interesting one. Toxic Taste makes the green fire poison enemies, and Double the Fun makes each keg explode twice at the cost of having fewer kegs out at once.
Take Toxic Taste. Poison is one of the harder statuses to get your hands on in this game, and having it sitting in your evolution is worth more than the raw explosion count. Double the Fun has a case in Nightmare Mode, but the rest of the kit leans area of effect, so it is fighting itself.
One build note. Area of effect makes the kegs visibly bigger, so it scales the way you would hope.
Powder Kegs are a fantastic early game weapon. If you are new and you are willing to spend the gems as a free-to-play player, go for it. I think that one is worth it.