It’s the final stretch. The Reign of Jafar is just under a week away from its official debut release on the 30th of this month. And we’re now closing out this expansion’s Amethyst line-up.
Madam Mim - Up to No Good & Poe De Spell - Magica's Brother

We’re starting out this list with some rather unexciting inclusions. Both Up to No Good and Magica’s Brother are fairly standard and usable if a body is all you need, but in the likely scenario that you'll need more, these won't cut it.
Druun - Ravenous Plague & Royal Guard - Octopus Soldier

Druun is an above-statted creature should you Challenge with it, but frankly, it's not very exciting, either. Octopus Soldier, on the other hand, can be looked on a little more favorably as it is a 1 ink cost to justify its stats. In a draw-focused strategy, this can trade up into something a lot more expensive.
Bruno Madrigal - Single-Minded

Bruno Madrigal plays into the control aspect that Amethyst likes to do from time to time. Unfortunately, Single-Minded shares the same ink cost as current Amethyst staple, Genie - Wish Fulfilled.
Depending on the win condition of the deck, this slot is already tight as it is. Single-Minded’s one turn delay for a single exerted character may not be enough to convince players to run him, set rotation or not.
Megara - Part of the Plan

On her own, Megara is pretty robust for a 3 ink cost card. Her 5 Willpower gives her immense staying power that most others in the same weight class don’t get to enjoy. This will, hopefully, give you enough time to get Hades down, turning Megara into a big threat.
Part of the Plan may not see any use unless the player specifically has a copy of Hades in their deck list though. Even then, the card still pales in comparison to other cards competiting for the 3-ink portion of an Amethyst deck's curve. Besides being a decent body, Megara doesn't really offer anything.
The White Rose—Jewel of the Garden is an example of a stronger 3-ink card.
Yelana - Northuldra Leader & Ryder - Fleet-Footed Infiltrator

With respect to their ink costs, both Northuldra Leader and Fleet-Footed Infiltrator are fairly average.
The latter has Evasive to allow more leeway for the Lore race. The former can pair up nicely with an already established board on the challenge front.
For the current rotation, there’s hardly a reason to run these cards at the moment.
Ravensburger is angling to slow the pace of a match down to create wider boards with their recent card designs. Players might want to keep an eye out for Northuldra Leader once set 9 comes around to take advantage of this design choice.
Elsa - Fierce Protector & Jiminy Cricket - Level-Headed and Wise

It seems to be a trend for Amethyst’s in-house tools to be a little more on the average, if not a little subpar, side when it comes to their stats for their ink cost. Elsa is the former, Jiminy Cricket is the latter. But both enjoy some niche abilities.
Fierce Protector’s exertion capabilities are a little suspect due to its discard cost. Being able to open the path to assassinate priority targets, however, can come in handy.
If Amethyst's partner color already plays into the discard (Steel) or has recursion (Amber), then it’s not so bad in the grand scheme of things.
Jiminy Cricket’s existence in a deck is pretty difficult to justify. His ability to delay Rush characters can be useful but this value is limited by what the opponent is using. In the current rotation, the number of characters with Rush who see actual play is very limited. Unless this changes, Jiminy Cricket is unlikely to see much play.
Nero - Fearsome Crocodile & Monstro - Infamous Whale

Fearsome Crocodile does a fine job in emulating Amber’s healing capabilities while keeping to Amethyst’s natural antics. Unfortunately, its ability is hampered by its exertion cost. This turns Nero into a painfully average card with an ability that is hard to justify.
Monstro essentially offers a body capable of removing multiple creatures on impact. Thanks to Monstro's ability to ready itself, you can take out multiple characters one-by one via challenges in exchange for cards. This is, unfortunately, offset by a very expensive ink cost.
But there is some versatility to be had. If push comes to shove, Monstro can pull double duty of in either singing songs and challenging opposing characters.
Using Monstro to sing is pretty unlikely to happen once the late game is on its way, but it’s still a good option to have if you’re running the Infamous Whale. This card seems interesting, but it's tough to tell for sure if it will see play.
Camilo Madrigal - Center Stage

Camilo Madrigal offers Amethyst some surprising recursion for its ink cost. With an average stat line, Center Stage makes sure that challenging characters don’t come out of the exchange with just flesh wound.
And if its banish conditions are met, Camilo can either be reused for board presence once again if cards need to be withheld in hand or be fuel for the building inkwell for the later game cards.
Scarab

Scarab essentially offers an infinite value machine for decks using Illusion characters. The downside to this, aside from the Scarab's uninkable nature, is the sheer cost of using this engine. Requiring three ink to recur an Illusion, decks using Scarab need to go super late in order to make this card worthwhile. That said, this can become a powerful win condition under those circumstances.