Torchbearer

Since the day 0 patch pretty much nerfed the shatter combo, I use mixed. Although the only frost attack I get now is frost nova, for its ability to freeze buildings. Other than that one ability, fire all the way.

So far my preferred build for TB (Which I'm liking as my main preferred DG) is to get fireball and ice storm, nabbing the aoe stun at level 15ish.  Shatter IMO isn't worth anything, and the 10 second fire AOE is too unreliable compared to ice storm.  For equipment I just buy the first +HP item in each item class and the 10% speed boots.  +25 damage are gauntlets also a nice boost for a cheap price.

Since his fireball/icestorm and such are so powerful and such low cooldown, the only thing he needs is to be able to survive long enough to burn his enemies!  The more HP the better!  His mana is inherantly high, so I never see the need to buy +Mana/mana regen items.  Mana regen is efficiently replaced by the +3k mana pots if need be.

Rest of my money goes to pots, scrolls, and team upgrades (I always start off with +10 HP/sec for towers + 1 rejuv pot).

Likewise! Maximized frost nova, fireball, enhanced attributes, and circle of fire (for the mana boost). The remaining points are put into fire nova. (Only 1 point greyed out.) The passive fire ability gets no points at all.

I have yet to decide if I should take 1 point from Enhanced attributes so I can max out Fire nova.

I never bother with maxing Fire Nova. I put the points into maxing out the passive fire trait instead. Increased damage, attack speed and movement speed. I don't use Fire Nova as a damage dealing attack, I just use it to charge into a group of minions and send them flying, so the level 1 Fire Nova works fine for me.

As for items, I always equip my Anklet of Speed favor item and buy the boots of speed. 25% speed boost, yes please! I like to have the ability to get in and out of combat quickly. It also makes dodging Rooks' hammer slam a lot easier.

TB is becoming my favorite DG, i go pure fire for the most part, i did try putting points into that ice skill that lets you unlock fire and ice at lvl 15, the fire ball damage increase was awesome and with just decent gear i was hitting 1500 fire balls on everything, but im not sure if its worth all those points spent in that 1 ice line.

i also tried out a build where i max fire nove,fire circle AND get the cloak of flames for its on use ability..wanna see things burn down fast? try that out. save fire ball as the finisher while they are undoubtfully trying to run out of that aoe damage of ownage. that build also makes minion/reinforcements obsolete as they die in seconds. also with fire circle maxed out the mana boost it gives means you'll never pot again, i played a game VS nightmare AI with a friend (3v3) the game ended when i was lvl 17 and while inside the circle of fire, i had 23k mana(i also had all fathers ring,storm bringer, and i think 2 different helms), which was overkill as i couldnt even spend it fast enough to see the bar move more than a sliver. it leaves you open to stack more HP items and less mana items.

i kinda play more kamakahzi though, dont realy stack move speed items, i just run in. AOE like a mad man, which usually causes the enemy DG to run after 1 or 2 attacks when he see's his hp and reinforcements drop so fast. i also like staff of renewal for the cooldown bonus. the only bad thing i find about this style build is no interrupt/stun, so early on i find DG's scrolling out/potting through my attacks, but late game it becomes so strong that by time they realize they need to pot, its almost to late

To offer a comparison, I play Ice TB. I take Rain of Ice first, then take fill in Ice slots when available, and Fireball when not.

Ice TB is actually very good lategame when doing citadel pushes,  because his Frost Nova has a gigantic stun range, and what used to be 2 towers, 1 DG, and 30 enemies is now a completely still collection of ice sculptures. It's not so much dangerous as incredibly disruptive. I actually managed to win a 2v2 game without getting one kill with this against a Senda and Queen of Thorns (that game was a little weird in a lot of ways. Generally Ice TB is pretty good at killing things).

I would recommend against going fire against enemy Rooks based on a couple games I've played. You can end up getting hit by Hammer Slam if you actually try to attack him with anything but a medium range Fireball, and that's a guranteed death right there. That's more of a new player issue I'm sure, but it bears mentioning.

FIRE FIRE FIRE!!! I go entire fire tree and get the -10% cool down favor item, -35% (or 25 can't remember) mana aura helm. Go to enemy demigod or gods circle of fire and then another circle of fire with cloak of flames fire nova and a couple of fireballs. Makes for an amazing god killer. Same thing on buildings.

I also recommend against going 100% fire in all games. From my current experiences, against specific matchups, it's a certain death to be a full fire TB (ok, depends on who you team with, too, and the skill in front of you).

For example, I played a Vampire + TB vs 2 x Sednas, and got litteraly owned... Couldn't outdps them enough to be useful at all.

We ended up losing the game, where with some more ice skills, i could have least push enough to be useful.

Since that time, i started relying on ice a lot more, and its definitely going better in late games (mainly because of stun and the 3x shatter effect combo with icy rain).