Tirion Fordring by SpectralDuke

Level 1:
Blazing Ashes: Quest talent. When Wake of Ashes hits an enemy hero, gain 5 damage on the initial burst of Wake of Ashes, to a maximum of 100. Reward: After hitting 20 heroes with Wake of Ashes, increase the length and width of Wake of Ashes by 25%.
Holy Fount: Quest talent. Gathering a Regeneration Globe gives Tirion 10 Holy Power. Reward: Collect 25 Regeneration Globes to increase Tirion's max Holy Power to 150.
Sacred Edge: Quest talent. Reward: Hit enemy heroes with Tirion's basic attacks 100 times to increase the Holy Power Tirion receives from basic attacks by 5.

Level 4:
Hammer of Light: Judgment slows its target by a percentage equal to half of Tirion's remaining Holy Power for 2 seconds.
Fires of Justice: Ground burned by Wake of Ashes deals an additional 50% damage per second to enemies.
Blessing of Freedom: The target of Blessing of Haste becomes immune to roots and slows for its duration.

Level 7:
Ashen Momentum: Tirion's basic attacks reduce the cooldown of his basic abilities by 0.5 seconds.
Blessing of Radiance: Blessing of Haste's cost is reduced by 20 Holy Power.
Sacred Ash: For each enemy hero hit by the initial burst of Wake of Ashes, refund 10 Holy Power (to a maximum of 40).
Rebuke: Activate to Silence target enemy hero for 1 second. 45 second cooldown.

Level 10:
Ashbringer's Fury
Avenging Wrath

Level 13:
Virtue's Blade: The cooldown of Ashbringer is reduced by 3 seconds and the empowered attack deals an additional percentage of damage equal to Tirion's Holy Power.
Divine Hammer: Using Ashbringer causes divine hammers to swirl around Tirion, damaging nearby enemies for 53 (+4% per level) damage per second.
Crusade: Using Judgment causes your next Judgment within 8 seconds to cost 20 less Holy Power and reduces its cooldown by 2 seconds.
Seal of Light: Blessing of Haste's target also gains an additional 20% attack speed for its duration.

Level 16:
Consecration: Allied heroes standing in ground burned by Wake of Ashes are Resistant.
Divine Judgment: Judgment deals an additional 10% damage for each 10% of his maximum life Tirion is missing.
Shield of Vengeance: Activate to become Protected for 2 seconds, preventing all damage Tirion would take. When the ability ends, Tirion explodes with holy light, dealing damage to all nearby enemies equal to the total prevented damage. 90 second cooldown.
Bane of Tyrants: Basic attacks empowered by Ashbringer deal additional damage equal to 5% of the target's maximum health.

Level 20:
Execution Sentence: Ashbringer's Fury Stuns its target for 2 seconds, then Silences and Blinds them for 4 seconds.
Wings of Judgment: While using Avenging Wrath, reactivate to charge to target enemy and Stun them for 1 second.
Divine Purpose: All of Tirion's basic abilities cost 10 less Holy Power and their cooldowns are reduced by 2 seconds.
Banner of the Argent Crusade: Activate to place a banner. Allied heroes near the banner have 50% increased health regeneration and deal an additional 25% damage. The banner lasts 12 seconds or until it is destroyed. 45 second cooldown.

Tirion is a hero I'd love to see in Heroes of the Storm, in part because he's one of my favourite Hearthstone legendaries and in part because he's a juggernaut in the Warcraft universe, controlling one of the most powerful neutral factions in the Argent Crusade. The obvious difficulty with Tirion is obviously that Uther's in the game, but Tirion thankfully distinguishes himself by using the Ashbringer, which leaves him open to have Retribution Paladin options to contrast Uther's Holy Paladin. So Tirion became an Assassin to emphasise the damage-dealing role.

His trait is deliberately meant to mirror Arthas' Frostmourne, since the two were archenemies in WotLK. Tirion uses Holy Power to differentiate himself from Uther more and also to play with a resource he can only gain by attacking or talents. It's akin to Sonya's Fury in that respect. I might possibly need to give him more Holy Power generators or buff the existing ones admittedly.

Wake of Ashes was originally flat-out called Consecration, but I borrowed a name from one of the Ashbringer artifact's abilities because it sounded cooler. The ability is meant to be Tirion's sustain option while also using the ground burned by holy fire image I love and wanted to work into him. It's also Tirion's waveclear ability. So it has a lot going for it, possibly too much.

Judgment is a straightforward single target nuke, so I gave it some more thought with the Holy Power for additional damage clause. That way you have to weigh up whether it's worth spending HP on Blessing of Haste for chase, or if you think you can finish the enemy off with an empowered Judgment.

Blessing of Haste is Tirion's chase ability and very simplistic since the idea is to buff it with talents like Seal of Light to make it better.

Ashbringer's Fury was inspired by Tirion's breaking of Frostmourne, and the intent is the same: it renders the target completely unable to strike back by disabling both their basic attacks and their abilities. It's essentially a 'kill this hero' symbol when you use it. It has the higher cooldown because it's so potentially powerful to take an enemy completely out of the fight for 4 seconds while still leaving them killable.

Avenging Wrath got the other heroic slot because it's an iconic Paladin ability. Its purpose is basically to make Tirion into a monster for 8 seconds by letting him spam everything as fast as he generates Holy Power. I may add a clause to it giving Tirion more HP generation during Avenging Wrath to help with that, though it's nasty as it is.

Banner of the Argent Crusade happened because of Varian. I love his banner mechanic and decided to give Tirion a version of it to reflect the Argent Crusade.