This mod was originally made by TactWithMolag for SSE and backported by me thanks to generous open permissions.  The description below is from the original modpage.

Mephala is known for convincing others to betray people, so this is my attempt at making that happen, as it doesn't appear anyone else did this exact thing yet. When equipping the Ebony Blade, you should get an ability that's frenzy and a combat buff. It doesn't make the player go crazy of course, but it might just make a passive NPC attack others, if they held the blade. When unequipped, the ability goes away, so disarm is always an option once you decide you want your sword back.

You attack 33% faster and move about 45% faster.

Should be compatible with texture/mesh mods for the Ebony Blade, but I don't know as for enchantments. MO2 didn't show me any conflicts, so I assume it will be fine. Even if it isn't, the Ebony Blade will be better than vanilla thanks to Mephala's Whispers.

There will be an ESL file to take no space in your load order, or an ESP if you'd rather. Choose one, install as usual. No requirements other than base game.