On the Elder Scrolls Wikia it breaks down what perks from which of the two trees effect each. Like the damage is from 1-hand, but the "cut off heads" is from 2-hand.
So I'd have the Ebony Blade, plus probably a 1-hand Blades sword with sixy enchantments on it.
I'd go dual casting spells for range, 1-hand/spells for multiple targets or when I'm sticking & moving, and Ebony Blade any time my health gets low, or I'm fighting something like a Dragon Priest/Dragon thats landed/or any powerful spellcaster.
Meh, the only reason I wanted Ebony blade was because there was no Akavir-Dai Katanas like the one I used in Oblivion, but two things completely went against my character.
You had to be Evil to make it Stronger, and it was based on One-handed damage

Remember that the Katana gets stronger if you kill innocent people.
So my re-make of my Main character
(the Khajiit with the Two-Handed & Frost Destruction Build) won't even touch the sword or it's quest o.o