Quiet moment for more catch-up feedback.
Runic Haste. I like Enhancement as your solution to 2-for-1 loss of Enchant Equipment. I appreciate that a quick action Hunting Bow could not be used twice (only quick spells may be cast with QC marker). However, I am wary of enablers like this. A future full action ability could become broken with this so its existence restricts future design.
Archivist v2. Looks good. I like this feeble old man challenging: "I shall defeat you with my extensive knowledge of mainly level 1 spells".
Magisbane, the Purifier v2. It's now too expensive. I like Magisbane as a "mana magnet" idea of Upkeep +1 and this cost is countered by its Mana Drain 2 of opponent. As it is, I would reduce its cost to 10 (same as level 3 Sectarus, its opposite).
The Book of Secrets. I love it's concept. However, even once Dissolved, its damage is done, the spells are obliterated. Also the first spell may be Dissolve (especially as equipment is low level Archivist-friendly). I would not make it permanent but more synergetic with Archivist abilities. Something like "Opponents cannot cast the same spell as those at the top of all discard piles. Discard piles cannot be shuffled. When an opponent casts a spell, during Counter Spell step, if you have the same spell in hand, you may reveal it, discard it and pay mana equal to its level to counter that spell." Opponents have to work around a changing temporary spells injunction but also a cheap anticipate to counter benefit. Also, as an Archivist Only item, I would make it Arcane 1 (1 spell point, not 4).
Crystal Ball. I'd make it Planning Phase so you can use the information. I don't normally like memory mechanics but this is manageable.
Prophet. As you know, I dislike memory mechanics. Precognition should just be "When you have Initiative, your opponent must reveal 2 choices during Planning before you choose your spells". In the same vein, I think Anticipate should be "When you don't have Initiative, at the end of Planning, name 1 spell. Opponents may not cast that spell this round." The On/Off mechanic is to allow mirror matches and both mechanics are information based, not mechanical which seems too corporeal for a divination-based mage. I'd give him 32 life. Also Prophet is Holy, not Arcane. I'd make him or her a Seer or a Soothsayer or some other divination-based mage subclass. Prophets don't carry a Crystal Ball, they are divine messengers. I'm sorry that, unlike Archivist and Dreamwalker, I'm not a great fan as it is. However, a divination-based mage is a great idea and I urge you to rethink.
Predict Fate. I love the flavour text! As for the effect, I think you have got a typo as it doesn't make sense as is (24 mana?). I would make it target "Any object" for total versatility and "Reveal only during Deployment. Name any card (including a mage). If an opponent destroys this object with that named card while this enchantment is attached, gain 10 mana. Destroy this enchantment at the end of the round." I think it's currently very fiddly with all those Fate counters on enchantment and its creature etc. The concept of Predict Fate is hard to execute.
Artificer v2. I like. I think this Dwarf artificer from Ivarium (love the choice) would simply be trained in War and Arcane 1, Nature triple, he is neutral and Arcane is always better (e.g. equipment). I like the new mechanic but the package is bit weak for a 9 mana mage as it triggers on duplicates after you wasted mana. How about his second ability as "Gadgeteer. Each Deployment, you may replace 1 equipment with new equipment in the same location by paying mana equal to its extra cost or the replacing equipment's spell level, whichever is greater." He is still reliant on Battle Forge for quick equipment deployment but this is neater and does not leave him at a huge mana disadvantage when switching items around. Which is his "shtick".
Magisbane Golem v2. I like the Lumbering upgrade on an Iron Golem. I like the concept of an Attack Spell magnet but it's too powerful as a nullifier. It's made out of Magisbane, this anti-magic matter. I think you should remove "Lightning +2, Acid +2, Tough -6" and the middle sentence of the text, instead add "Enchantment Immunity. Incantation Immunity. Attack Spells -2" as keywords. Attack spells can damage it but lose 2 attack dice and -2 effect die. Currently, it's a bit broken. I really like your anti-channeling and attack spell magnet mechanics.