The book of ahsur is a 35ss arcane item that adds +1 to each cast and dispel attempt. It is an item that is rarely used in warhammer because it is difficult to defend the bearer with only 30 points of gear, and previously slanns would buy extra PD instead. I think the new book gives us an opportunity to revisit the item. Wandering Deliberations - all of the spells are at 10 or less casting cost with boosted versions in the teens. Normally you would three dice a 10+ spell because the 28% chance to fail and lose concentration is too great, but this has an 8% chance of miscast. Three dice enough spells, and it will happen over the course of the game. This has caused players to remove their slann from the TG bunker because the risk is too high. Earthing Rod and Soul of Stone won't help because a 7 or less blows away 100-200 points of temple guard into the warp wounds any Vets. +1 Casting So how does the book of ashur help? You can two dice every spell with wandering deliberations, reducing your chance of losing concentration on a 10 to 17% (1/6). Your miscast chance drops to boxcars, 1/36. Now you can leave your slann in the TG bunker, and you can three dice boosted Burning Gaze and Fireball. You only need to leave the TG bunker to four dice boosted seeding doom. When faced with this, your opponent will quickly realize that you can cast 4-6 spells a turn by two dicing away his DD and then 1 dicing until you lose concentration on fireballs. This discourages them from trying for ID and also encourages dicing (and possibly failing) instead of burning scroll caddies. The +1 casting increases the chance of failing to dispel. Imagine the look on your opponents face after you roll two-dice an 11 and inform him he has to beat 16 to stop wyssan's wildform. Synergies and Gear So the book of ashur lets you leave the slann bunkered the entire game, how best do we leverage that? Eldritch Battery or Becalming Cogitation for offense vs defense Obsidian Amulet/Unfathomable Presence for MR Mask of Eee!/Harrowing Scrutiny for terror BSB, with flaming, mr(1), skavenpelt, etc. Note that the hatred against the bearer for skavenpelt will never happen! Personally I'm a fan of lichebone pennant + flaming banner with obsidian amulet, becalming, and harrowing scrutiny. Give the slann flaming so you duck out against 2+ dragonhelms. This makes the TG 3+/4++ vs magical wounds - even in my turn - and 6+/2++ if you get off earthblood against heavens magic, fire for buildings and regen, and terror. Since WD has spirit leech to snipe BSBs and ice shard blizzard, the terror/fear might actually do something. Add a ScarVet to take challenges and you'll have a death star with strong magic and magic defense that is only vulnerable to war machines. +1 Dispel The +1 dispel is a nice bonus, but is harder to take advantage of. The main use of book of Ashur is in your magic phase and list building. You aren't going to start saving DD just because of the +1. That said, it does interact with Eldritch and Becalming. If your opponent flubs a roll, say rolls a 5 on three dice, you can two dice him and then pocket the 3rd dice. Your opponent may also resort to IF more often, leaving you with unused DD. +1 PD in your phase is essentially +1 successful spell casts. One dice miasma, one dice iceshards - something you can cast last as a nice-to-have spell. If you stack MR, you may choose to let through any magic missiles and also save dice - this isn't unique to the book but the book allows you to bunker and stack MR. Obviously, becalming becomes more reliable with the +1 dispel. If you flub a roll you just might tie, and even if you don't you can reroll and make it count. Dwarves and L2s The saying for the last book was that lizards were OP in magic and Dwarves were OP in dispel. When the armies clash, the lizards magic phase was merely average. Does the book of Ashur pass this test? Does it flip the game? Dwarves often get a four dice swing and on average rolls have 8 DP to your 6 or 7 if you take eldritch battery. The book of ashur gives a margin of +3 to casting attempts and by two dicing spells you can draw out 3 DD and get an advantage. His eight dice might stop three spells and your six dice can get off four - 2, 2, 1, 1. Spirit Leech, Fireball, Iceshard, Miasma would be a good rotation and every spell has a chance and you could swap spirit leech and fireball for wyssans and earthblood in melee. I think that counts as an average magic phase, no? TL;DR - Book of Ashur lets you two dice a deliberations slann, lets you leave him in the bunker fo to low miscast chance, and can mess with your opponents dispel dice if you can pick off the L4. This is a spendy build that costs about 500 plus the TG, but it is a block you can base your list on.