Nadine Eskiy

I just realized how effectively Nadine Eskiy combos with Negotium too.  Between Nadine and Negotium, your opponent will probably only have 1 or 2 people who can actually oppose you at other stories.  Negotium ties up the little guys, and Nadine ties up the big guys.  Now you can just concentrate your removal on the medium-sized guys, and you've got unopposed stories for days!

I won a regional a few years ago with a Yog-ST negotium deck, and i think you want as many three cost characters as possible in any such deck. Nadine Eskiy is decent, but Faceless Abductor, Peaslee, Black Dog, and Master of Myths are all higher impact in the same slot.

If the "same slot" is getting a character into play for a cost less than three in the opening turns of the game, you'd be right. But I think the implication of Track8's suggestion may have more value in the later game, when Nadine can play siren during your opponent's turn to suck into Negotium all the potential defenders for your turn, thus generating the desired unopposed stories.

Of course, your opponent will probably only make that mistake once, never committing to Negotium on his turns thereafter. But still. And she is doughty in the opening turns. 

Peaslee is a nice idea, and I like how the Master of Myths would work with Negotium.  My deck is going the Yog/Shub Sorcerer direction.  I like Nadine working with Negotium and Lady Esprit, and I like Slenderman working with Negotium and Nadine.  There's a lot of synergy in there.  Lost Oracle keeps Slenderman around, and frustrates my opponent's attempts at getting rid of Negotium.

Peaslee is a pretty neat trick though.  I could see that being really effective with Negotium.

If the "same slot" is getting a character into play for a cost less than three in the opening turns of the game, you'd be right. 

The "same slot" is characters that cost less than 3 that either can get get around Negotium (stalking hound is another one) or removes your opponents 3 cost characters. Nadine is okay at this, although unless you're playing against ancient ones, most of the threatening characters are going to have 3 skill.

I'd be very excited to see Lady Esprit in a Negotium deck, particularly in a meta where Negotium was commonplace, since it basically demands that 3 cost characters become the default.

Slenderman seems a bit questionable since he basically just does the same thing as Negotium (keeps 2 cost characters out). Possibly he would be useful against rush? But Negotium is best used to stall until you can get out your weenie-stomping AOs or to set up a delayed rush where you'll probably win before your opponent could win Negotium anyways