The theme has a certain charm, but Tyrael’s trait is, unfortunately, plain bad game design. And why? Because it requires you to die to get any use out of it.
Tyrael’s trait, Archangel’s Wrath, is bad for three reasons:
Tyrael is a tank. The tank’s job is to take blows meant for others, yes, but it’s also to survive longer than anyone else and thus disrupt the enemy lineup. Getting full use out of the trait means you have to do the one thing you’re NOT supposed to do, i.e. die.
Since dying is the only way to get any use out of the trait, this means that if you play well (and your team plays well with you) and you never die, your trait contributed absolutely nothing to the battle. You may think “Isn’t it a good thing that you never needed it?”, but the answer to that is “No!”. You wouldn’t be happy with having other abilities or traits locked out on other heroes, so why would it be acceptable on Tyrael?
The HotS dev team themselves have previously acknowledged why this is bad design, though perhaps without realising it. There was a talent that let Archangel’s Wrath heal allies when he exploded, but it was removed. The reason: The dev team didn’t want to “encourage builds that rely/depend on you getting killed” (paraphrase). So even the devs clearly know that it’s a bad idea. Lets just change the sucker already!
A simple rework that fits both Tyrael’s combat style and theme
Tyrael is the Archangel of Justice (at least the one we have in HotS is). And what is more just than paying for your crimes?
Replace Archangel’s Wrath with a trait literally called Archangel of Justice:
When Tyrael takes damage from enemy Heroes, he is surrounded by an aura of retributive justice, dealing X damage to nearby enemy Heroes every 0.5 seconds. This damage is increased by +2.5 % for every 1 % of maximum health he suffers in damage while the aura is active, to a maximum of + 250 % damage. After not taking damage from enemy Heroes for 3 seconds, the aura fades over 4 seconds.
This reworked trait has three clear benefits:
It fits his theme of Justice much more than the current “Archangel of Suicide Bombings” trait.
It encourages him to take damage on behalf of his team, and encourages his team to help keep him alive in teamfights.
It synergises incredibly well with his kit of high mobility and diving into the enemy lineup. If they focus on trying to kill him, they will suffer moderately high damage for doing so.
If you want to keep parts of the functionality of his current trait, you can add a talent that makes his aura reduce enemy damage dealt depending on its current level of strength (making him tankier and more support-y, but also lowering his damage output since the enemy wont be hurting him as much), and add another talent that lets him keep moving after death (just as he does now) and for his aura to keep damaging enemies during that time.
It’s not a complete hero rework, but it would make a sizeable difference for Tyrael, and make him more of the offensive tank he was meant to be.