It’s essentially a better Blade Splicer, which still sees play in many lists. It also is likely to do more lifting than Aven Mindcensor.

They do, although I will say they mostly fail only the “regular” Bolt Test and not the expanded one I defined here. Even if those creatures die to Bolt, they have huge impact on the game and/or create value regardless of whether or not they die.

Yeah, that’s where I am too. Vial on T4 is really horrible, and a natural T3 cast isn’t great either.

That argument is rampant online. I see it literally every time a creature with < 4 toughness gets previewed and multiple people evaluate the card as "bad; dies to Bolt." I wish it was just a lame straw man, but it's actually the argument people make. I also hear it ALL the time in-person. If she's playable, it's because you can drop her T2 on a dork. If that's not good enough, then I agree she' snot going to make the cut.

You’d be surprised—I’ve heard and seen plenty of people describe the Bolt Test that way. I agree with you that Thalia seems very conditional and therefore pretty bad.

Note Thalia affects nonbasics only. It’s still annoying with fetches, but when mana is needed most will be able to get a basic.

Personally doubt she’s playable – if it had been 2 cmc for a 2/1 with this effect then yep but as is – not likely

Oh yeah, Unsubstantiate is another one I’m curious about as well. Seems at least worth looking into.

I am currently forming my opinion about that card and some others. Will be doing a preview article next week in all likelihood.

I disagree with your comparison, as Pridemate never gains trample, first strike, or lifelink. Pridemate can grow to the moon but get chumped by tokens or mana dorks all day long. Rider stops at 4, but presents a more significant threat (not to mention being able to flip later copies of itself). I know it’s easy to stop after the commonality of “2-drop that grows from lifegain”, but ignoring three very relevant keywords is a mistake. On top of that, Pridemate needs to hit the table before the lifegain happens, while Rider can be put down after you know he’ll flip; and Pridemate wants multiple triggers while Rider only needs one.

Now, I’m not saying I’m convinced it’s Modern material, but it’s too different from Pridemate for that to be a valid comparison.

Rider is like a more conditional Ajani’s Pridemate. Maybe 1-2 could fit in the deck as Pridemate’s 5-6, but I’m not optimistic. It’s better in the RW deck versions where you can T2 Rider and T3 Helix with one mana up for something else. My big problem with Rider is that its unflipped side is very low-impact at 1/1. Pridemate typically lands as a 3/3 or bigger with a Sister in play, so he can tangle with Guide, Nacatl, and other Burn/Zoo creatures.