Tiadrin is a interesting hero in that she is designed to counter lich, but does a poor job at it. Lich players mostly only use scorpions and spiders which are magical creatures which makes them take 50% less damage to magic damage, which Tiadrin deals out. Tiadrin will melt undead units such as skeletons but no one uses them. Tiadrin is useful to kill enemy player castle’s with her ability to damage players walls if they are a lich, this is helpful when you have a high level whale bullying the server you can band together and spam Tiadrins ability on them and kill that whale.

Judgement Seal (costs 1 mana)
Tiadrin places 3 Judgement Seals on the battlefield, dealing X damage to enemies for 7 seconds, with bonus damage to Undead Units. Damage from multiple seals cannot be stacked. Bonus based on Magic
Trash spell don’t get it.

Glory Hammer
Each time Tiadrin attacks there is a 25% chance of summoning a Glory Hammer from the heavens that deals X damage in a small area and stuns enemies, with bonus damage to Undead Units.
One-point ability anymore points would only be because you can’t spend points in other skills.

Purge the Lands (costs 1 mana)
In Adventure, immediately reduces the DEF of a nearby Lich Territory by X%. The ability cooldown is 10 hours.
Amazing for slowly killing a whale who plays Lich, very effective if you have a few players doing it twice a day, you can keep a player out of the game pretty much. I can see this skill being removed/changed in the future.

Divine Light
Tiadrin automatically casts divine light to heal a nearby Hero with low HP, healing for X HP each time. Tiadrin cannot cast divine light on herself.
This skill is actually pretty good, it will fully heal any hero and if used on a hero like Bane who is designed to take a lot of damage it actually helps win battles.

Aura of Retribution
Tiadrin mastered the Aura of Retribution, dealing X damage per second to enemy units on the battlefield, with bonus damage to Undead Units.
If you plan on playing a delaying battle strategy than this skill is made for you.

Sacrifice (costs 3 mana)
Tiadrin sacrifices 70% of her current HP to summon 1 massive sword that smashes into the ground, dealing X damage to enemy units in range, with bonus damage to Undead Units
This spell hits like a truck but also basically kills you, and since Tiadrin is a melee hero she will get herself kill after you cast this.

Building Tiadrin
Tiadrin is used as a field dot damage and that the primary thing you want to focus on so Max Aura of Retribution. And put one point into Divine light as it can fully heal any hero and if used properly can turn the tide if cast on a tanky distraction hero like Bane or Rufio. I would also get one point into glory hammer for the added damage. I am a big fan of leveling Purge the land as most Whales play Lich and you can use this ability to kill that whale slowly over a few days, if you have enough players doing this with you.

Equipping Tiadrin
Tiadrin needs all four stats that a hero can get so just put your best leftover items on her.