This is my first time making a guide. So do not yell at me if something I add is not meta or competitive enough. This is a judgment on my own gameplay and what I see to be the best.
I will, however, welcome helpful criticism, maybe something a bit more to give this build that extra punch.

Lastly, this build was played mainly on Blitz, so it might not work the same on 5v5 or 3v3

As this is in Blitz mode (is not added on the wiki) you'll be able to level up quickly. But in a normal 5v5 or 3v3, I suggest leveling up your Merciless Pursuit first, then you Stormguard second, leveling up your ultimate as soon as you can. Take the overdrive on Merciless Pursuit and Blast Tremor, unless you are facing opponents with high damage output, then take the overdrive on Stormguard instead the last upgrade for Blast Tremor.

When you start I suggest getting health items first, such as Oak hear and whatnot. Leveling up your health will help you become a very strong punisher class that can take a beating, your crystal damage will come later.

Do not forget to stun enemies as well to raise your heroic perk, this will help immensely.

Now since your here, you should have, hopefully, one of the following; Crucible, Capacitor Plate (Or Rook's defense if needed) or War Treads.
At this point, your Ultimate should be upgraded to the first level. Focus your efforts on getting Broken Myth. Broken Myth is a great shield piercer and will act as a warning, saying, "You better back the hell off, or we will kill you!"
Next, GET CLOCKWORK.
I'm sure you have noticed that your energy isn't exactly spared to all of this heavy attacking, so clockwork will help a lot with energy and cool down!
Lastly, you will want to get Spellfire. This item is overpowered. Alongside the massive attack boost to your abilities, you'll inflict Mortal Wound, which paired with Blast Tremor, will punish even the most foolish of players.

You are NOT built for killing someone.
I know, I have told you to get a bunch of items to deal massive damage. YOU DO NOT KILL! You're more of a tenderizer, beating the meat for your allies to take the kill, so first thing first, DO NOT ENGAGE TO KILL!
Yes, you will kill enemies at times, but you're built for the assist and getting enemies off your allies' backs.
Suppress every urge to kill and instead be a human shield, since Stormguard and punish an enemy for attacking way too much.
If you like going for the kill, dont use this build