Star Student Stelina doesn't seem nearly as good as Glide to me. You're only disrupting 1 card for 4 mana, not to mention you have to wait for it to be outcasted to get the effect. On top of that, the ideal use for this hand disruption is against control/combo decks, which usually have moderate hand sizes and can afford to lose 1 card if that means you made a not great tempo play of a 4 mana 4/3. What makes Glide more powerful is that it does more for you and against the opponent: drawing 3-4 card ideally and shrinking your opponents hand size by a few cards is way more substantial for 4 mana than a 1 card disrupt on a 4/3.

Instructor Fireheart is more impactful than Vulpera Scoundrel on turn 3 and on any turn after. I imagine that any Shaman deck that isn't totems would love to run her as she can usually act as both efficient tempo and efficient removal. Consider the fact that Shaman is limited in card draw and resource generation options and Instructor Fireheart is a home run.

Nature Studies is a solid inclusion in Spell Druid. Helps you get your tempo swing with Glowfly Swarm out a turn earlier and can even find you another Glowfly Swarm. You'll usually find something that helps your game plan off of Nature Studies and it helps you chain spells for Exotic Mountseller.

Cycle of Hatred is a spell that is the jack of all trades but the master of none of them. Chaos Nova does more removal damage for 2 mana cheaper if you're a control DH that cares about AoE, and there are a handful of cards the remove a threat and generate tempo earlier in the game (i.e. Glaivebound Adept and Illidari Felblade to name a couple). Standard Hearthstone right now demands that your deck if full of cards that are the masters of a game plan, and Cycle of Hatred just isn't that.

I think Cobalt Spellkin is better as a dragon with spell generation as its 1 mana cheaper than Onyx Magescribe, doesn't require another card to trigger the generation, and the spells are more easily playable. Maybe Onyx Magescribe gets its chance to shine when Cobalt Spellkin rotates?

If you're playing a Druid deck that cares about buffing your deck, as that's what most targets of Survival of the Fittest will be, why not just run Embiggen instead? Embiggen can be played earlier in the game, allowing for more buffed minions and for those buffs to be more impactful sooner as well as the fact that you don't need a 4 card combo with Kael'thas Sunstrider if you wanted the Survival of the Fittest buffs earlier. Embiggen is just more efficient and consistent for a buff game plan than Survival of the Fittest.

Runic Carvings just seems underwhelming in both classes. In Druid, it gets outclassed by Glowfly Swarm. In Shaman, its slower and not as sticky on board as Totem Goliath (plus it breaks a potential Totem Shaman build of curving into Totem Goliath on 5 with Lorekeeper Polkelt on 4). This spell is a jack of all trades but a master of none of them, which doesn't cut it in standard Hearthstone these days.

Totem Goliath is very scary on turn 5, especially since it can be followed up with Totemic Reflection or Splitting Axe if not removed or a board buff if it is removed and the deathrattle activates. Lorekeeper Polkelt can increase the consistency of curving into a Totem Goliath on turn 5 with the followup of either another one, an activated Vessina, or Splitting Axe, the latter 2 of which can be played even with the 2 overload (just don't run Bloodlust). I think Goliath and Polkelt could seriously push Totem Shaman to Tier 1.

Frazzled Freshman makes sense in a Tempo Buff Priest, but the real question is will Tempo Buff Priest make sense as a deck and in the meta. The main issue with Tempo Buff Priest is that they're all in early game with no way to reload midgame except for Sethekk Veilweaver. If cards get introduced that fix this problem, then I think the archetype as well as Frazzled Freshman will see play.

I don't see why you would run Cabal Acolyte over Cabal Shadow Priest. While Cabal Shadow Priest is 2 more mana and doesn't have taunt, the effect is targeted and doesn't require another card to trigger. I think if you consider running either card you care most about the effect, and Cabal Shadow Priest is more resource efficient and more consistent in what it steals.

Goody Two-Shields looks like it easily replaces Bronze Explorer in Libram Paladin. Great stats with Divine Shield for 3 mana and the Spellburst effect is the icing on the cake. The fact that you don't need to trigger the Spellburst effect for Goody Two-Shields to be good just makes it a go-to 3 drop for any tempo Paly deck that isn't Murlocs.

The weird thing about Ancient Void Hound is that the more the minion benefits off its effect, the more likely the DH playing it going to lose the game. Ancient Void Hound doesn't do anything to protect the DH the turn they play it, and if their opponent has a wide board the opponent can just usually end the game even if they lose attack on their board. Against slower decks with less minions, the effect does very little and the DH spends their entire turn developing it for it to be removed most of the time by their opponent, giving the opponent initiative. I just don't see an effective use for Ancient Void Hound anyway I slice it, despite how crazy the stats and effect appear to be.

Forest Warden Omu looks scary. Playing it with Germination gives you 10 free mana instead of 4 free mana on 10 mana crystals. This allows for combo potential with Malygos, especially if Malygos is discounted by Imprisoned Satyr which would allow for Malygos to be copied and have 10 mana left to cast spells at your opponent's face. The extra Malygos isn't even necessary if you set your opponent to 15 with Alexstrasza the turn before.

There is a natural check for Maly Druid if it becomes competitively viable: it is weak to tempo/aggro, which has made up most of the past 2 expansions' metas. I don't imagine a Maly Druid being higher than a tier 2 deck in Scholomance.

Lord Barov looks powerful, but I think with a little context he doesn't appear as good as his face value.

First, the deathrattle for Lord Barov needs to be triggered the turn you play him if you want to clear the board that turn, which I imagine will be most scenarios as is the nature of board clears. This means you need another card alongside Lord Barov to kill him like Teron Gorefiend or Rocket Augmerchant or that new broom card. The issue with this is that this is a 2 card combo with the core card being a one-of in the deck, which makes your activator(s) dead in hand until you draw Lord Barov,.

Second, for Paladin, the Equality effect has historically seen play in control and combo Paly decks, where you aren't playing for board. Paladin right now, and standard Hearthstone for that matter, is mostly about playing for board. Libram Paladin would rather run Libram of Justice as it doesn't ruin their board like Lord Barov does. Also, there just isn't enough support for a control or combo Paladin in standard right now.

Third, for Warrior, I actually think its possible for Lord Barov to see play in Warrior as they have self-damage enabling effects and have run enabler cards like Teron Gorefiend quite successfully in Ashes of Outland. Still, Lord Barov is awkward with Inner Rage, Rampage, and Bloodsworn Mercenary and could be a dead card in hand if any of these cards are also in hand.

Overall, I think Lord Barov is more situational than he looks. If control or combo for either class gets support, than his inclusion in either class would make more sense.

Gift of Luminance fits pretty well into both Libram Paladin and Cube Priest in my eyes.

In Libram Paladin, its a great way to consistently get multiple copies of Libram of Wisdom without having to only rely of Lady Liadrin, allowing for those multiple Libram of Wisdom pressure turns to happen sooner.

In Cube Priest, this acts almost like a cheaper Psyche Split so its easily more usable with Grave Rune in the same turn, allowing for those sticky boards to happen sooner.

Also, Gift of Luminance counts towards the discount on Devout Pupil, which also works great in both decks.

If you're referring to Shadow Word: Pain than yes R.I.P. Alura, but there is a very interesting scenario where if Alura pulls Shadow Word: Death from your deck, it won't kill Alura if you didn't buff her to have 5 or more attack. Instead it will target another minion that actually has 5 or more attack on the board it can kill.

I don't see a reason a DH would run Magehunter over Consume Magic. Consume Magic is cheaper, can replace itself in hand by drawing a card, and isn't restricted by taunt. Also, the stat upside of Magehunter doesn't really matter as most of the time you care more about the silence effect, which Consume Magic does better. Maybe this sees play after Consume Magic rotates out with the DH Initiate set.

Keymaster Alabaster doesn't yield its benefits until your next turn, and that's really slow for a 7-drop without Rush or Taunt. Also, generally speaking, your more likely to get low-cost cards (< 5 mana) than high-cost cards (> 5 mana) across all decks as every deck needs something for the early game. I just don't see why any deck would want to run this.

First Day of School is effectively a 1-drop and a 2-drop in one card, just like how Fire Fly served this purpose in tempo decks of its time. Also can have some mid-to-late game utility with Kael'thas Sunstrider since its a 0-mana card that could cheat out spells like Lay on Hands and Libram of Hope. In conclusion, a very solid tempo card that I think easily replaces Imprisoned Sungill in Libram Paladin and has some shenanigan potential.

As everyone else has said, Devout Pupil looks like a great inclusion in Libram Paladin. So I'd like to focus on this card's applications in Priest.

I see this going mainly into one deck in Priest: Cube Priest. That deck would love a low mana Devout Pupil to use Grave Rune and Psyche Split on. Along with these buff cards, Renew and Apotheosis work towards the discount as well. Also, Sethekk Veilweaver and Renew can help generate friendly targeting spells. For Cube Priest, I don't think that the deck would need to alter its card inclusions too much to make this work really well, not to mention they are getting a new buff card in Gift of Luminance that works well with the deck and adds to the discount.

In a more straight up Tempo Priest, Devout Pupil could work, but the main issue with the archetype is that there is no efficient way besides Sethekk Veilweaver to reload on resources in the midgame after you've spent your entire hand on cheap tempo in the early game.