I have yet to use a Slann in this edition (and only used him once in the old) and was toying with the idea of getting one. My usual list has an Oldblood on Horned One and 2 EotGs in Suarus units, but I wanted to use a Slann BSB, 1 EotG and a Jaguar Scar-vet. I always run 2 units of Terradons and 2 units of 2 Hunting packs. The change for my Slann would include trading my usual 2 Saurus units and Skink/Krox for a Suarus unit, 2 Skirmish Skink units and a TG unit. So for my Slann build, I was thinking I would give him 4 disciplines (MR3, re-roll miscast table, no 6's for enemy wizards & of course the free power dice per spell). For his items would be Plaque of Tepok and at least 1 power stone, maybe more if I have points. My EotG Preist will have Diadem and a Scroll. This list is made to be anti-magic. I figure I can use the Jaguar charm at the beginning of my magic phase to lure out dispel dice, then start casting. On turns when I need the the Scar-vet to get around, I'll use the charm after casting all my spells. Alternatively, I am thinking of dropping the TG and just having the Slann alone (disciplines will then be: free power dice, re-roll miscast table, immune to all but magic, and regenerate). Any thoughts?
Well - a single Slann struggles to fight it's way through enemy magic. I played dwarfs last night and 9 Dispel dice are tough to fight through for a single Slann. Many Armies these days routinely generate 7+. If you want magic to be a major feature you'll need more than just the engine and the Slann. I recommend another skink - their useful for casting Magic missiles through and adding some more threats to the enemy lines.