My variant of the warlock was based of off DnD 4th Edition. Give me advice based on that, constructive or anything like that.
Major Skills: Destruction: Novice-Expert, Fire / Shock perks, dual cast and Impact to emulate Eldrict Blast.
Enchanting: Fire-Storm Enchanter, Insightful Enchanter and Extra effect for Pact Daggers.
Alteration: Novice-Expert, Stability and Atronach.
One Handed: 5/5 Armsman to emulate Pact Daggers
Sneak: 1/5 Stealth to emulate Shadow Walk.
As for gear, I'd use Ebony Mail to represent the Dark Pact, also I'd use a worn shrouded hood with fortify alteration and destruction and use those enchantments on a ring and necklace. I'd use fortify stamina and fortify sneak for shadow walk. My gloves would be enchanted with fortify magicka and fortify sneak.
For shouts, I would use Fire Breath for the Infernal Pact, Marked for Death for the Dark Pact, and Whirlwind Sprint for utility.
My pact daggers are as follow:
Gruumsh's Talon: Orcish Dagger with Absorb Health and Fire Damage.
Raven Queen's Shiv: Shiv with Fear and Shock Damage.
Tiamet's Fang: Ebony Dagger with Fire Damage and Fear.