Mage Ymir

This build prioritizes: health, mana, and damage. Everything you could ever need or want on Ymir. The health makes up the lack of defense and the damage is huge. The beginning is tricky because you need to play more of the supportive role and helping teammates and clearing waves. The mid to late game is when you switch it from support to one man army.
Ymir is a special guardian because he doesn't feel like one. He is a powerhouse of health and muscle.

Also hello FrostFangs!

Ymir's damage won't shine until mid to late game. Play cautiously until you get some stacks on Hide of the Urchin and Warlock's sash before making big plays.

Watcher's Gift- Ymir won't be wave clearing at the start so this item helps you stay ahead of the game with everyone else. It's only temporary for now, you'll sell it for gold later.

Hide of the Urchin- This is the only defensive item you'll need. The base stats are already good and will get even better when you help assist the team. While playing the start cautiously the extra defense will help you get some pokes in. You'll hold onto this item until you finish your Ethereal Staff because by then you'll have so much health and damage you won't be needing it. You'll be selling it for Rod of Tahuti as your last item.

Warlock's Sash- This is the starting point of you becoming unstoppable. The stats on this is insane for mage Ymir. At full stacks this thing offers 110 magical power, 600 health, and 400 mana. Even at half stack you should be fully clearing lanes by yourself now so go ahead and sell your Watcher's Gift for gold.

Obsidian Shard- Short and sweet, it offers more power and 33% pen for taking out enemies easier.

Polynomicon- Out of all the gods I would say Ymir gets the best out of it's effect. Using any damaging move on Ymir applies Frostbite on the target for a few seconds causing your auto attacks to deal 100% more damage. Add that to the 75% magic buff the Polynomicon grants you every 3 seconds and all the magic power you have gotten from your other items, your auto attacks deal insane damage to your enemies.

Ethereal Staff- With the 400 health this items gives you and the 600 health from your Warlock's Sash plus Ymir's natural health pool, that's a lot of damage from a passive.

Rod of Tahuti- Last but not least, this item tops off your magical power to it's limit. At this stage you're unstoppable, immovable, immortal. You will need to sell your Hide of the Urchin for this but that's not a problem. With all the health, mana, and power you won't be needing it. It will just hold you back from your true potential.

Relics- The first one is up to you, preferably Sanctuary or Purification. The second one is what makes this special. Blink. Yup, Blink. Nobody expects a decked out Ymir powerhouse blinking right at them destroying their every being. It can also be used to chase a enemy and place a wall in front of them helping a teammate secure a kill, or for escape. Ymir is slow and predictable so you need an edge against the enemy to counteract Ymir's slowness and be able to engage the attack for your team to rush in.

There are two ways to play your skills, your 2 or your 3. It's really personal preference and mine is 3. Yea the 2 does more damage for the lane clears but I find the stun duration on the 3 to be much more effective early on for securing kills for my team. My skill priority is 4-3-2-1 but it's up to you.

The best way to engage the enemy is to 3-2-1. Freeze them in place so you can aim your 2 better and place a wall right behind them blocking their escape. Try to body block as much as possible as well, make them go the long way around the wall.
The best burst for Ymir is to wait for the enemy to make the mistake of getting too close together. When you see the opportunity, Blink right in front of them and 3-2-1-4. You can cancel your 4 early for less damage if you feel like you won't make the full damage on someone running out. Don't be greedy.

Pros- -High damage to the point you can solo most fights by yourself

-High pool of Hp and Mana, you will rarely be in need of mana in your mid to late game

-No need to counter build, you can use the same one every time

Cons- -Classes with leap that can run away when you Blink at them, try to bait their escape move and then Blink. Same goes for your ultimate, try to bait their escape moves.

-The last couple of items are gold hungry, try to clear waves as much as you can if there is no one else stacking.

-Even with the high amount of health, the lack of defense can still leave you hurting. Play safe and smart and that won't be too much of a problem though.

This build ends you with the following.

Health-3590
Mana-2090
Magical Power-675
Magican Pen-33%
Phys Prot-89
Magic Prot-48
CD-10%

I love this build and I hope you do too. Let me know if you see and changes that you think would make it better. Happy clubbing!