Evelynn and Thresh as something like partners in torture.

There is a lot surrounding Evelynn as to what she is exactly, but most of what I've seen points to her being one from the Shadow Isles. As an assassin, I'd image she finds pleasure in killing and maybe even the suffering of her victims.

Thresh was a jailor before his death and transformation into a specter, but he clearly maintains a physical form. What if he were to find someone who enjoyed the acts of torture and death as much as himself?

For those wondering, yes this is me brainstorming about my next project for a fanfiction after I finish my current two.

Well...
I would have to say it would be pretty cool.
I don't see how it could involve romance in any way though, as I think you do often.
Let me double check it was you >_>
E: Yeap it was you. I was just curious as to how they would meet. Just Thresh chilling next the dead body of a man, it's aura becoming a soul he trapped in his lantern. He then takes it and summons it, then begins to torture it with his chains. Eve walks in and then what? Would be a bit awkward XD
E#2: The Naut and Nami, the Rengar and Nidalee (I have barely skimmed that one, sorry :<)

Okay... a few things:
1. What do you mean "it was me"? Could you elaborate?
2. Yes, I know it would be nothing romance related. This is the widowmaker as the main female role after all. It would be more of a bloody, twisted past-time both champions could enjoy.
3. Their meeting would most likely be as simple as crossing paths. Thresh picks out a target, one Evelynn has been hired to dispatch by a client, and, rather than fighting each other, they both torture the poor sap. Personally, I like to image Eve as part vampire, so she would take great interest in the fountain of blood as the target teeters between life and death, silently praying one of them slips up and ends his or her torment.

Only question would be who the victim is that could have political enemies who would hire the expensive assassin, and also catch the attention of the specter jailor.

I don't really like this idea. After all, these are killers. Cold blooded assassins. (executioner/jailer in thresh's case) I would think that most of the people of the shadow isles would be rather solitary people.
I wouldn't list her as a vampire since they never said she was. They only hint it.
Are you intending to just write a story of them mutilating the sh*t out of some poor soul? Because that really is kinda pointless.

But if you want my 2 cents, no, I don't think it would work. They would be like: "This is my victim. All mine."

*By "It was you" he was referring to your rather "romantic" pairings.

Ah, that's what he meant. And no, I would not make some graphic fan fiction of these two champions in question. If anything, it would be them meeting and developing a relationship, like what I did with my recent Nautilus and Nami fanfic.

And thank you FrostArcher024 for you insight.

Glad to help! I was thinking though, the great similarities of Thresh and Hecarim. maybe a rivalry? They don't have to be male/female you know... (and no, I'm not talking yaoi)

I know, I just prefer male and female pairings. However, I am kind of afraid of someone working on such a fic and finishing before me, as I like to retain originality.

As to making the rivalry fic, I can not get on the public beta thingy for whatever reason, tried several times and nothing. So I am forced to wait until Thresh is finished being tested before I can begin work on him. (I don't like watching videos for my research.)

O.O you play a lot of Co-op vs AI. But I don't know why Public Beta doesn't work for you.
I really like/admire your work. Could you make one of Garen and Kayle? :3

I want to see how you would make it and compare it with mine

Garen and Kayle... I could give it a try if I find the resources to make something happen.

Also, I tend to not like my teammates very much, in most cases, or I lag in games. So I play vs AI to know if I do lag, and then, if I have time, I will play a game or two of PvP. Either I am called away or I get tired of bad teammates. (I don't play ranked because of this)