(Note: This concept is obsolete after the announcement and subsequent release of Vel'Koz in V4.3, around half a year after Shu'Nak was posted here. Though their kits are fairly different, they occupy pretty much the exact same thematic and gameplay niche, and Vel is by far the cooler tentacled eyeball dude.)
Shu'Nak, Eye of the Void is an idea for a Void-themed support/mage, focused on laying down mass debuffs and crippling specific enemies. As a floating eye, eldritch horror-type champion, he can inflict a host of debuffs onto the entire enemy team, though he himself is very vulnerable. Though his abilities greatly help in teamfights, he can also use them to singlehandedly melt priority targets.
Enemies affected by Shu'Nak'sabilities are Cursed for 3 seconds and are slowed by 25% / 30% / 35%, decaying over the duration.
I wanted Shu'Nak to be able to mass debuff enemies, and so this allows him to either slow multiple enemies at a time with his AoE or focus on a single target. I also felt a slow would best work for his thematic as an evil eye, whose spells would cripple enemies.
At the same time, I didn't want this passive to be too crippling, which is why I made the slow moderately powerful and had it decay over a duration. That way Shu gets good harass and poke/chase/escape powers, but not to the point where he can completely immobilize his targets.
COST: 20 / 17 / 14 / 11 / 8 Mana
COOLDOWN: 8 / 7.5 / 7 / 6.5 / 6
Active:Shu'Nak's glare goes forth in an expanding cone, dealing magic damage to all enemies hit and reducing their armor and magic resistance for 3 seconds.
A skill a little similar to Mordekaiser'sSiphon of Destruction, except that it travels forth as a wave and has a larger range. This is meant to be Shu'Nak's primary poke, harass and waveclear in lane, as well as his initiation tool besides his ultimate.
COST: 23 / 19 / 15 / 11 / 7 Mana
Active:Shu'Nak spawns a flurry of tendrils from the target location, dealing magic damage to all enemies around the source.
Though the ability's range turns it into a good poke, Void Tendrils' strength lies in its ability to combo with Shu'Nak's other skills to root targets. It's meant to be fairly versatile, as you can combo it off any other ability.
COST: 21 / 17 / 13 / 9 / 5 Mana
COOLDOWN: 14 / 13 / 12 / 11 / 10
Active:Shu'Nak fires a blast from his eye which travels forth in a line, providing sight as it passes until it hits an enemy, dealing them magic damage, silencing them and revealing them.
Considering Shu'Nak has no gapclosers or defense, I wanted to give him utility that'd allow him to perform bush checks. When supporting, this is meant to especially help with chasing down targets, including stealthed ones, and check for ambushes.
COOLDOWN: 110 / 100 / 90
Passive:Cursed enemies take magic damage every second.
Magic Damage per Second: 10 / 15 / 20 (+ 10% AP)
Active:Shu'Nak focuses his gaze on the target enemy champion for 5 seconds. While he has sight of them, they take amplified damage from all sources and are continuously Cursed.
Damage Amplification: 15 / 20 / 25%
If the target dies while affected by Fatal Stare, all enemies near the victim run away in terror.
For a champion whose stare is meant to inflict terrible omens on the battlefield (a la Eye of Sauron), this seemed like a pretty fitting ultimate. The fear also plays to his theme while also adding both extra reward to scoring a kill and extra counterplay. To keep with his theme, I wanted to make the debuff conditional upon Shu'Nak having vision on the target, also allowing for counterplay options there. As I intended Shu to be played as either a mage or a support, this helps both builds: the first by allowing him to melt targets by himself, and the second by amplifying the damage taken by critical targets in teamfights before CCing the enemy team.