Quoting trankillity, reply 2TBs aren't fantastic DG killers, they're more about control. Fireball doesn't do that much damage, in fact UB spit does more damage at max rank. There's also lots of counters to Fireball because of the long cast time (Stuns/Shields). The only time you can get a lot of burst off on a DG is if you go Frost and get the 3x Shatter bonus. I have found Frost to definitely be the best all-round focus, plus you can shoot on the move with Frost form.
That being said, you still need to bounce between forms whenever you're not fighting in order to keep up the weapon damage and mana regen buffs.
Another quick tip: If you're Fire and an enemy DG is running from you after you hit him with a Fireball, jump into Frost mode. It only takes 0.5s and you can fire on the move then plus you get the weapon damage buff. Switching to Frost was well thought-out by the designers in this regard, definitely something to kill runners
I'm saying this as a non-UB player.
I always see this, about how UB spit does soo much damage. If you have enough HP/s, which you should, or atleast something that can give you health, the UB spit is kinda weak IMO. It's the only move (off the top of my head) that has it's damage reduced by the enemy demigod (HP/s). If it's ticking for 115 and I'm regenning 30, it's only ticking for 85 effectively. Consider the heals coming from your priests and other DG's and it really doesn't equate to that much. I actually fear fireball much more because if I have less than the health that it hits for, I'm dead when it lands. Not as true with UB.
Just wanted to add that as a result of fireball doing somewhat less dmg than spit, TB can be a better killer. It is more often a question of using your abilities with the right timing. If you start with your dot (such as circle and normal atk) most are just going to view it as soak dmg... nothing to worry about yet. You throw in an early fireball, they might be inclined to stay in it because they think it doesn't do as much dmg... but keep in mind recasts, and other abilities (such as fire nova). You don't have to weather as much pounding agaisnt each other, because within that 15m radius, you have a tremendous burst dmg ability.
By the same token, as one of only three ranged attackers, a TB with +weapon dmg and + attack speed can be quite deadly, precisely because of the native 15m range. When you attack twice per second for 400 dmg for 15m, it's hard for anyone to escape fast enough without having a stun or backup ready... which they probably already used on you.
