8th Ed. Which Disciplines of the Old Ones to Choose?

[Orchid]

I'm planning on adding a Slann Mage-Priest to my collection soon. My hobby group isn't particularly competitive or anything, so I'd like to see what I can do with a more expensive and decked-out one in a Temple Guard bunker. I was wondering which Disciplines of the Old Ones you have all had success with, as I'm having some trouble narrowing it down.

So far I think I want Soul of Stone for some miscast control, Harmonic Convergence (Channeling Staff combo), and Focus of Mystery. I'm mostly caught up between Reservoir of Eldritch Energy and Becalming Cogitation for my fourth. Any thoughts? Thanks!

 

[Xuil]

Those are nice choices so far.

I've frequently found myself taking Becalming Cogitation and it not ever getting used, so my last game I took Reservoir instead, and realised how much that safety net actually means. Your dispel phase really suffers when you can no longer risk dicing that nasty dispel and HAVE to use your scroll. If the odds are about 50-50% of making the dispel AND you get a re-roll, it's sometimes worth saving your scroll for an even more dire situation!

Soul of stone is another of those disciplines which may never come into play. I'm lucky never to have gotten my slann sucked into the warp, but then I usually run him solo or in a skink bunker, so the template results are not a worry.

 

[Sandrockkai]

If you're already planning on the Harmonic Convergence/Channeling Staff shenanigans, then you likely won't need the Reservoir of Eldritch Energy. I'd say take Becalming Cogitation if you've got the points to spare, since it's significantly more important for your dice to be efficient in your opponent's magic phase.

Those are my two cents.

 

[Orchid]

Alright, thanks for the help! I'll take Becalming Cogitation and see how it goes.