The Skyrim Ebony Blade is a two-handed weapon found in Dragonsreach in Whiterun Hold.
The Ebony Blade is a Daedric artifact belonging to Mephala, resembling an Akaviri Sword or Blades Sword. Killing kinship with the blade reinforces its power. Unless instructed to kill an ally, followers can wield the blade, but can not fortify the enchantment. The blade itself is a nodachi style Kanmuri-otoshi, with the back drastically thinning out, possibly due to a false edge, about three-quarters of the blade from the hilt up.
The Skyrim Ebony Blade is obtained by asking Hulda, the barkeeper at The Bannered Mare in Whiterun, if she’s heard any rumors, in the Daedric quest “The Whispering Door,” which can be initiated after reaching level 20 and completing the “Dragon Rising” quest. Ysolda, who has since taken over the inn, will not start the search if Hulda is killed. In this case, it can only be started by using the setstage DA08 10 console command.
Can it be upgraded? The answer sadly is no. It is not possible to upgrade the blade. This is explained in the Admonition Against Ebony, which states that “Not even the hottest fires of the Skyforge could melt it; indeed the coals themselves seemed to cool when it was placed within,” revealing the immunity of the sword to heat or normal forging/smithing techniques.
So…What about The Skyrim Ebony Blade enchantment? This weapon begins with a 10-point enchantment of Health Absorption that can be enhanced by slaying friendly characters. For instance, the blade can absorb anyone whose favor has been accomplished or who has been won over during any kind of quest. The weapon’s Absorb Health enchantment increases by four points for every two such characters killed. At a maximum of 30 Absorb Health points per hit, killing ten friendly characters maximizes its power.
According to Fandom, “Characters who say things like, “With you around, it’s a nice day.” or “You’ve been a good friend to me, that means something.” The Dragonborn is considered friendly and will count as a charge up. Another sign is whether to take low-value items as theft from their home counts or not. Anyone to whom, through a dialog option (not the barter menu), the Dragonborn sells firewood, ore, food, or alchemical ingredients will become friendly.
Through dropping a sword or a piece of armor anywhere, the Dragonborn may also make friends, causing characters to approach them and inquire whether the object is free for the taking or not. Saying “yes” is going to make them friendly. You can max out the Skyrim Ebony Blade.