Essence Reliquary is a nice Crystal Shard variant I missed from MH3.

All the rooms (Surgical Suite // Hospital Room, Bottomless Pool // Locker Room, Painter's Studio // Defaced Gallery) are just cards that have been in this cube before (Recommission, Fading Hope, Goblin Oriflamme) that additionally put other spells in your hand when you play them.

Brightblade Stoat is better enough than Knight of Meadowgrain that it's worth trying over what is usuallt a sideboard card, despite the different modes.

Sheltered by Ghosts is a really nutty removal spell, almost seems too good on paper.

Parting Gust is what Getaway Glamer always wanted to be.

Dewdrop Cure seems like an insane amount of value for one card.

White Hordeling Outburst is a much more reasonable card than Battle Screech, but I'm worried that Neighborhood Guardian is still too strong, even after de-powering tokens a bit.

Unnerving Grasp synergizes with spells deck, and you still get some blink shenanigans with it if you manifest a permanent.

Plumecreed Escort... Remember when we were playing things like Welkin Tern? Floodpits Drowner certainly doesn't.

Splash Lasher is interesting over Mist Raven for the 6-mana mode, and the fact that it plays nicely with Sharae of Numbing Depths.

Get Out is interesting over Exclude for letting you get back some ETB effects.

Eddymurk Crab is a much better finisher than [[Shipwreck Dowser, I think.

Kasimina, Enigmatic Mentor is good, but kinda slow. I like that Shoreline Looter is kind of a combination of Looter il-Kor and Enclave Cryptologist.

Fell has so many fewer words on it than Power Word Kill that I think the downgrade to sorcery is worth it.

Hollow Marauder has an ETB, has evasion, and lets you keep the cards in your graveyard to reuse later.

I missed the second half of Etched Slith's text box before and don't want to include narrow-ish hosers. Thought-Stalker Warlock is straight fire.

Speaking of fire Brazen Collector, dang. Reckless Pyrosurfer was kind of a placeholder.

Flamecache Gecko is better than Stormblood Berserker when you fail to trigger bloodthirst, and letting you play 2x 2-drops when you do is a comparable benefit.

Heartfire Hero is a good card for the modified deck, RIP to Stonewright, you were a real one.

Norin, Swift Survivalist is a great 1-drop, remaining relevant lategame in being able to mess up combat and re-buy your ETBs.

Galewind Moose is certainly an impressive pile of stats.

Hivespine Wolverine is, I think, a more interesting version of Acidic Slime, and more fun to play.

I'm not sure Rx decks need Stump Stomp enough vs the extra benefits Hunter's Talent provides.

Under the Skin is an interesting Eternal Witness variant, opening up some neat lines for the GB graveyard decks.

Oblivious Bookworm is a much better early drop than Gretchen Titchwillow, actually letting you kill 2/x creatures, and letting you start drawing extra cards immediately.