Archon as warlord

I’m looking for some help. I’m running a list with three patrols, one from each sub faction, and at first I was planning on a Succubus being my Warlord to use Dark Lotus. But then I read a rule that required my Archon to be a warlord or he couldn’t do something, and I thought “Well, then my Archon needs to be the warlord!” The problem is that I either I can’t remember what that rule was, or I was just plain wrong, because now I can’t for the life of me find a single reason why I would need my Archon to be my warlord to do anything I want him to do.

Am I actually forgetting something, or did I make this whole thing up? Anybody have any insight here?

If I recall correctly, it's just a prerequisite for a Realspace Raid detachment.

It's also a prerequisite for the Alliance of Agony stratagem that your warlord is an Archon in a Realspace Raid.

The above replies have the right answer. For this reason, in a Raiding Force, not having your archon as your WL is often the better way to go. It obviously depends heavily on what obsessions you're using and the general strategies you plan to use. But, for instance, if Drazhar is in your list, he should probably be the warlord. If you want to then pay CP to give the Archon a WL trait, go for it!

We need to double check the following: If your warlord is Archon, you can still take a relic from the Book of Rust for your CoS Succubus using the stratagem, while your free relic is from the codex.

My understanding of the current rules are as follows:

Realspace Raid - If your Archon is your Warlord, you can take Relics from any of the other subfactions within the Realspace Raid (ie it unlocks Dark Lotus Toxin in Cult of Strife). This is a rule of the Realspace Raid. However, since this is not a "cult of strife detatchment", you CANNOT use the CoS Strats.

Raiding Force - You can make the CoS Succubus your Warlord, and use both the CoS Relics and Strats. Also allows you to take Drazhar (since you have the HQ slot available with the patrols).

Most people going for the Raiding Force for this reason

I hope this helps