Having recently purchased Arkham Horror and all expansions at Gen Con (my roommate who had owned everything moved to Massachusetts...), I designed a series of scenarios that would (eventually) use every investigator, every herald, and every Ancient One. By random chance, Glaaki has been paired with Tulzcha for the next game. Based on my searches of this forum, there has never been an official ruling on how to handle this pair, since Cultists would have to be both Stalkers and Elusive elder sign seekers. So, since there's no official ruling, what do people think is the most fun way to play this?

My thoughts are:

1) Cultists are Undead (no contradictions there)

2) Cultists will be Elusive (so you don't have to fight them), but will move like Stalkers (so they'll follow investigators if able).

3) However, Cultists will choose to pursue an Elder sign over pursuing an investigator (so that Tulzcha's effect still matters).

What are other people's thoughts on the matter?

On the rare occasion this pair has shown up, I do it exactly as you have listed. The Cultists may be Undead Stalkers as per the "Boss", but the "Foreman" is commanding them to remove Elder Signs, and that's their priority.

Besides, a removed Elder Sign versus a Cultist you don't even have to fight? Allowing the Investigators to possibly deliberately PULL a Cultist away from an Elder Sign is a GROSS VIOLATION of Arkham's Razor (paraphrased: "Do whatever hurts the Investigators most.") Such an act would likely cause forumite Steve-O to burst a vessel in a Sanity Token.

Your three points are the ones I'd assume. Taking out elder signs is priority over chasing investigators. Otherwise, you could tactically put an investigator adjacent to a Cultist and lure it away from an elder sign it would otherwise go after.

As for the Elusive/Stalker conundrum, the proto-FAQ just says they move toward investigators as stalkers normally would. But Elusive monsters are supposed to ignore investigators for the purposes of movement (meaning they'll leave an investigator's space if they move). Clearly for this to work you have to ignore the rule that elusive monsters ignore investigators for purposes of movement. But, an investigator still has to initiate combat.

The cultists will maintain some facets of the Elusive and Stalker traits You'll still have to pass an evade check to engage one in combat and they will still move towards you if you are at an adjacent location but if they're adjacent to a location with an Elder Sign, they'll move to that location, disregarding their Stalker duties. Because I think removing elder signs is their main priority in the game with this herald, and where the challenge factor is derived from.