Jormunngundr: Oh lawd, he comin' (Arena/Clash)

Jormungundr is a relatively new guardian with some interesting possibilities. Depending on your build decisions, he can be a punishing weapon or an infuriating tank. His passive adds a unique way to manage enemy crowd-control.

Jormungundr's basic combo takes the form of:
Venomous Haze->Submerge->Consuming Bellow

Venomous Haze creates a puddle of toxic sludge on the ground that damages and slows enemies who walk through it. It also sets up the secondary effect of Submerge. By submerging and erupting up in the puddle created by Venomous Haze, Jormungundr will create 2 additional, slightly smaller puddles. This sets up additional bonus damage and range for Consuming Bellow if it is cast within range of up to 3 puddles.

Finally, Jormungundr's ultimate ability allows him to chase weak enemies with punishing damage or escape conflict. Since The World Serpent involves 3 leaps, you can deliver damage and flee combat in one use.

Immovable
Jormungandr is so large that he cannot be affected by Hard Displacement instead he gets Dazed. Dazed is a debuff on Jormungandr that is a fading slow and increases the damage he takes for the duration. Any Attack speed past base reduces the cooldown rate of Jormungandr’s Basic Attack.

Slow: 20% fading over 2s
Increased Damage to Jorm: 10%
Duration: 2s

Venomous Haze
Jormungandr fires noxious spit at an area that deals damage and creates a large toxic cloud. This field damages and slows Enemies inside of it every second. Jormungandr can have a maximum of 9 toxic clouds out at a time.

Initial Damage: 80/120/160/200/240 (+40% of your magical power)
Cloud Damage per tick: 5/15/25/35/45 (+5% of your magical power)
Slow: 15%
Slow Duration: 1s
Cloud Duration: 20s
Cooldown: 16/15/14/13/12 seconds
Cost: 60/65/70/75/80 mana

Consuming Bellow0
Jormungandr draws power from toxic clouds nearby while channeling for 1.2s. At the end of the channel, Jormungandr roars dealing damage to all Enemies, trembling and slowing Enemy gods by 30% for 1.5s. Each cloud increases the size of Consuming Bellow and Empowers him up to 3 times while also dealing extra damage to Enemies hit. Extra damage after the first instance is halved. While Empowered, Jormungandr’s basic attack fires at its fastest rate.

Damage: 120/180/240/300/360 (+50% of your magical power)
Bonus Damage: 20/30/40/50/60 (+10% of your magical power)
Max. Stacks: 3
Slow: 30%
Slow Duration: 1.5 seconds
Cooldown: 14 seconds
Mana Cost: 70

Submerge
Jormungandr submerges into the ground turning invisible as he searches for prey. During this time he moves faster and gains predatory vision, sensing all enemies in a large radius. Firing this ability while invisible reveals Jormungandr as he emerges out of the ground, knocking up Enemies around him. Taking damage from Enemy gods also breaks the Stealth.

Damage: 70/125/180/235/290 (+50% of your magical power)
Movement Speed: 25%
Duration: 5s
Cooldown: 18 seconds
Mana Cost: 70/75/80/85/90

The World Serpent
Jormungandr prepares to enter into the world, enlarging as he prepares a devastating attack. After selecting a target area, Jormungandr flies into the air, diving down and crashing into enemies as his body then slams into the ground. He must travel 2 more times. When Jormungandr Emerges and Submerges during this ability, he knocks up Enemies and with each Submerge he leaves behind a toxic cloud.

Submerge Damage: 150/200/250/300/350 (+40% of your magical power)
Emerge/Crash Damage: 75/100/125/150/175 (+20% of your magical power)
Cooldown: 100 seconds
Mana Cost: 100

Pros:
High health
High sustain (supported by lifesteal or regen)
Highly mobile ult
High burst damage

Cons:
Low mobility outside of ult
Being dazed makes you very vulnerable

Jormungundr's strength lies in his sustainability. With high health, and considerable damage output from his abilities, as well as an AoE basic attack, he is capable of handling enemies gods and controlling minions.