In my search for a viable build for Arthas, I found that I had to experiment and come up with one on my own.

It's paramount to see what composition your enemy has when building Arthas. The three builds I've created boil down to three purposes; sustained damage, high survivability, and a hard counter to Nova and/or Zeratul.

Note that, for each build, I will always recommend Summon Sindragosa. Some are going to swear by Army of the Dead, but this right here has so much more utility.

Winning the teamfight? Freeze enemy runners.
Losing the teamfight? Freeze enemy chasers.
Fighting around the enemy's structures? Freeze the structures.
Fighting around your structures? Freeze the enemy near your structures.
Defending against a huge minion/merc push? Freeze the enemy minions/mercs?
Need to defend an objective? Steal the initiative from an enemy attack.
Need to attack an objective? Initiate with a freeze.

Now, on this one note, your mileage may vary: I never seem to experience that feeling of, "Oh, I wish my heroic wasn't on CD." I swear, I'm using this all game, but it never seems to be on cooldown. Those 80 seconds go by so quickly.

The biggest concern you should have with this talent is timing it, which simply comes down to practice. Make sure enemy interrupts have already been used or are out of range. There's nothing quite as disappointing as getting stunned and having to wait 10 seconds to pop off that heroic.

And if that's not enough to convince you, on a personal level, if I have ever needed to use Army of the Dead to maintain my health, it was already too late at that point. The CD between heals just seems way too long.

Sustained Damage

When to take

If you're facing a non-traditional comp, such as multiple tanks/healers/split-pushers, you're going to bring the pain. This will allow you to fire-and-forget your Frozen Tempest. This is my favorite choice for solo QM.

I'd also recommend this if you have another Warrior on your team, as it allows you to fill in a damage gap.

Talent Breakdown

Eternal Hunger: Keeps you in the lane/fight, plain and simple.

Frozen Wastes: 3 mana per second sure adds up over a 15-25 minute game.

Rune Tap: This, combined with Frostmoure Hungers, allows you to lane for recovery. Clear a wave or two and you're ready for another bout. Much better than having to B and ride back.

Summon Sindragosa: See Heroic

Biting Cold: As if the slow wasn't enough, it's time to bring on the hurt! AoE damage is a beautiful thing. This will aid in teamfights, lane-clearing, and you can position between forts/keeps and their towers for even more damage.

Immortal Coil: Why should you ever choose between loving yourself and hating your enemy? Now, you don't have to. Lay down the pain and heal yourself at the same time. And for when you're about to get Pyroblasted from a soon-to-be-dead Kael'Thas, pop that self-cast for an even more potent heal.

Rewind: This is where the magic happens. This is also why you're grateful you took the extra mana from your D and the reduced cost for your E.
Miss your W? Try again.
Land your W on a Li Li, but couldn't lock down the kill? Try again.
Need a bunch of health really quickly? Here you go.

* If you notice that you get focused quite often, feel free to trade Rewind for Hardened Shield.

Sustained Survivability

When to take

This is going to be for when the enemy team has a pretty traditional comp and you need to ensure that you're there to tank for your team.

Talent Breakdown

Regeneration Master: Passive regen is a must to stay fit between fights. This keeps you away from your spawn and closer to your team when they need you.

Frozen Wastes: As mentioned before, the amount of mana saved here is tremendous.

Rune Tap: 1.04% max health every hit (delivered as 3.12% every third hit), great combined with a nicely-timed D.

Summon Sindragosa: See Heroic

Relentless: You are the Lich King! You will not be cast aside during the fight. When they think they've put you in time-out, you get right back in their face and show them otherwise.

Immortal Coil: As above, this is just too juicy of a talent to skip. Damage + Heal or Super-Heal. Great utlity + guaranteed health.

Hardened Shield: They want to focus you? Forget about it. Just make sure you time it correctly.

Stealth-Counter

When to take

This build is identical to the high survivability, with only two substitutions. If you believe you're going to be going up against a skilled Nova/Zeratul, this is the build to take. Especially so if they're doing a combo. They will learn to avoid you. They will learn to avoid the teammates near you. They will learn to despise you and question whether they should just take the leaver penalty.

Talent Breakdown

Block: Oh, Nova, you went Anti-Armor Shells? That's cute.

Frozen Wastes: Not even Oracle is better as revealing stealthers and keeping them from re-cloaking. This guarantees you'll be able to keep them visible and you'll be able to slow them during a chase. Just make sure you learn to be ever watchful for the stealth shimmer.

Rune Tap: Health is important.

Summon Sindragosa: Not only the above mentioned, but it can reveal and slow cloaked enemies near group fights.

Spell Shield: Triple Tap or Singularity Spikes are nothing more than light tickling to the Lich King.

Immortal Coil: Seriously, why do I have to keep justifying this? Just take it already! Especially against squishy cloaked people.

Hardened Shield: When it's late-game and Nova and Zeratul decide that they're just going to combo you to death, prepare to laugh.