Damage Ymir - Hit like a tank, literally.

Hello and welcome to the wonderful world of damage Ymir, also known as: Ymir is actually a mid mage, follow your dreams. In all seriousness though, Ymir is easily my favorite god, and one of the first gods that many players choose to experiment with builds on. Let me get this across early on: You will not be tanking hits with this build. You will end up with roughly 2300 or so health, and that will go away pretty quickly. Your job is to pop in, deal absurd damage, hold people down in teamfights, and get out.

Typically, you'll see Ymir in the support role, but (what a surprise!) that is not the only role Ymir can play. Ymir has the damage and CC to easily play either solo, duo, or even jungle. All it takes is a little creativity and the ability to break away from the rigid mindset that says to build certain classes only one way.

You may have figured it out by now, but Ymir, oddly, has some ridiculous damage for a tank, and that is exactly why we love to build him with damage.

Now, I tend to play Ymir on duo lane, and that's the position I'm going to be writing this guide for. In my personal opinion, damage Ymir is far more useful as a support than tank Ymir. The absurd damage and slows should leave enemies weakened and immobile, allowing you to easily feed your hunter.

Rather than the traditional Ymir build, stacking defense and whatnot, I made a different choice.
I built him to hit like a truck. Now, Ymir has some nice damage output, and perhaps you could jack your magical power up higher, but in order to shine, Ymir needs to go for max cooldowns immediately.

Starting with cooldown boots allows for Ymir to start doing some decent damage immediately, and buying yourself a handy-dandy little Chronos pendant allows you to spit out a Glacial Strike every 4 seconds.

Next on the list is Polynomicon. It's not for the negligible lifesteal, nor the power increase, no no no. It's for the passive. Poly's passive works hand in hand with Ymir's, adding another wonderful chunk of damage on top of the 100% increase from Frostbite. this means, for the first hit on an enemy who has Frostbite on them, you're dealing your base damage, PLUS 150% of your magical power. Ouch.

Obsidian Shard is a relatively straightforward item, you're getting it to cut through armor like butter, nothing more to say.

Soul Reaver is there for a similar reason as Poly. Chunks. Soul Reaver's passive (Every 60 seconds, your damaging abilities will deal 15% of an enemy god's max health in damage). That is a free 15% of their health, on top of your already hefty power.

The final item, the ever so lovely Rod of Tahuti is rather simple, it increases your magical power by 25%, ensuring you hit like a truck.

On the side of actives, Blink (Either combat or greater, personally, I would recommend greater, its more for engaging than running away).

One of my favorite things about Ymir is his passive.
Each one of your damage dealing abilities will leave a debuff on whoever is hit by them called Frostbite. Frostbite not only applies a fun little slow to keep them from running, but also causes your melee attacks to inflict 100% more damage for the duration of the debuff.

Now, Ymir's primary damage dealing skill is going to be his 2, or Glacial Strike. Given that with this build, you will have extremely short cooldowns, you can throw it out rapidly, to clear lane, deal damage, slow enemies, all the good stuff. Pump this at every level you get, max it to level 5.

Ymir's 3, Frost Breath, is going to be used to initiate fights, to hold your target in place for a Glacial Strike, and for the rest of the stun, you can just beat on them with your melee. Most of the time, you won't deal enough damage to finish them off, but hey, that's what your ADC is for. They can easily do the last bits of damage and claim the kill. I'd heavily advise against engaging when Frost Breath is on cooldown. When you can't level Glacial Strike, level Frost Breath.

Ymir's 1, Ice wall, is usually his least useful attack, is generally kept on the backburner for this build. You will level it once at level 3 and then forget about it until you're forced to level it. Until you've gotten used to Ymir, his wall can easily be more of a hindrance. Typically, one is going to use it to pop a wall behind someone, charge in with Frost Breath, pop Glacial Strike. Very rarely will you use your wall in combat, typically one will use it to retreat. Once you have completed boots, you can place your wall behind you whilst running to block yourself off.
Be very careful when using the wall, as it can quickly save your enemies, and prevent you from getting a kill.

Ymir's ultimate, Shards of Ice, is an interesting ult. Unless you can keep an enemy stunned and inside the ring, it won't do much damage.
At any point after initiating Shards of Ice, you can press LMB to fire it off early, at reduced damage. You're going to want to keep your enemies inside the ring for as long as possible before firing it off to maximize damage, generally by popping Frost Breath and walling them off from an easy escape.
You're rarely ever going to get to fire off Shards of Ice for full damage, as it takes a really long time to get to that point. It's better to actually hit it for reduced damage, than to risk not hitting it at all.

Remember to actually use your ultimate whenever you think you can, as you have max cooldowns, it comes back very quickly, and what's the point of having cooldowns if you don't spam it at every chance you get? It's incredibly useful for finishing off weakened targets before they can get away, as well as in teamfights.

Pros:

High damage
Good CC
Very easy to feed an ADC
Able to hold your own easily
Very flexible
Incredible lane clearing
Surprisingly durable for not building any protections (Innate tank protections, as well as health)
Can play almost every single role (ADC -Yes, you can make hunters into YOUR support, haha-, support, solo, jungle. I guess you

You might be durable for someone who built no protections, but you're still squishy. You're not going to be taking hits much.
Difficult to play well

In all, damage Ymir is a very fun and interesting build, if not slightly difficult to pull off. Ymir has very high damage, and a lot of slows and a VERY long stun, building him with damage allows for one to capitalize on that.
I would not recommend this for beginners, as it takes some good game sense to pull off well, you have to know when to use your skills and when to run.

Thanks for your time, and I hope you have some fun with this disgusting build.