Seriously, consider this. Cicero was obviously the most standout character in Skyrim. He left a lasting impression as just being so crazy and over the top.

Since TES VI will most likely take place in the future. I think he should come back as a spectral assassin that you can summon. Obviously as a special ability you get from the dark brotherhood, just like you could with Lucien Lachance (in the Skyrim darkbrotherhood questline).

I want this to happen badly. Cicero was the best character from Skyrim.

I most certainly don't and hope he is laid to rest forever. I found the character completely irritating and avoided him at all cost.

Personally I liked several other Skyrim characters better than Cicero.

But my real worry is that this would turn into a fan-service gimmick. Skyrim gave us Jiub, Maiq (yet again!), Neloth and Lucien Lachance as a summons. That's already a bit much, in my opinion. I would rather Bethesda create interesting new characters than bring old characters back.

Serana was far more memorable despite her complaining.