How do you play a Skyrim Nightblade? What skills do you focus on?

I can't really model anything after the old Nightblade class since many of those skills are gone now. The Skyrim NPC Nightblade class is set up with:

3 points Destruction, Sneak
2 points One-Handed, Alteration
1 point Light Armor
Attributes evenly increased

I kind of didn't want to use Destruction since every mage I play uses it a lot. I would like to try Illusion, but honestly I don't know what good those spells are.

So how do you play a Skyrim Nightblade?

Thanks!

My current playthrough could be considered such.

Khajiit sneak/assassin

Most perks are in stealth, one -handed, light armor

Some perks - pick pocket (for thief quests and I like to use it, plan to respec it laters), lockpick (working towards unbreakable), restoration (main healing ability)

Planned to add: archery or destruction (ranged attacks vs dragons), alteration/illusion (benefit spells - waterbreathing, invisibility, detect X; illusion perk silent casting)

I use Conjuration, specifically for the Bound Weapons. Because of that, I use One-Handed and Marksman skills since I use Bound Sword and Bow.

IMO Illusion is a must, but personally I only use Invisibility. Other skills I use is Alchemy, Lockpick...I think that is about it. I never really was fond of the idea of Destruction on a Nightblade.

I can definitely see using some Alteration spells. Illusion ... well I've never tried getting enemies to fight each other. Don't know how effective that really is.

You don't need destruction, replace that with illusion conjured bow/sword, muffle and invisibility but you can also summon an atronach if the excrement hits the fan