I can't believe Crucible of Worlds didn't get a reprint in this set. It's a Legacy and EDH staple and the price tag on it is outrageous for what it does.
I also 100% thought Mirage fetches would be in this set, but I'm not super-disappointed by that like I am with Crucible.
This is pretty stellar in Pauper EDH, since black's best asset in that format is the ability to repeatedlyrecurcreatures, so having relevant ETB abilities is important.
Use any of these on Momir Vig, Simic Visionary to make his text effectively read "Whenever you cast a green creature spell, search your library for a creature card, reveal it, put it into your hand, then shuffle your library." and then combo off with mana elves and Intruder Alarm/Earthcraft/Cryptolith Rite/Tangleroot.
Playing 49-land Ashling the Pilgrim against Sliver Overlord (at 72 life thanks to whatever-the-black-lifelink-sliver-is-called) and Nekusar, the Mindrazer (at 10, he just played Omniscience but doesn't have enough mana to follow it up with Nekusar and wheel us to death), I am at 2 life and need to really topdeck something truly great to not die. Ashling is on the battlefield with Darksteel Plate and 3 counters, and I have a ton of mana thanks to Extraplanar Lens and Sculpting Steel copying it.
This is a card that seems like it should have some sort of powerful application somewhere but I have no idea where that would be, other than infinite mana.
This isn't even really good in 60 card constructed, especially compared to Glimpse the Unthinkable at the same CMC. If you think of milling like burn, this does an effective 2.64 damage to an opponent for 2 mana (assuming they kept a 7-card hand) whereas Glimpse does an effective 3.77 and can also be used on yourself to fuel graveyard shenanigans.
So yeah, this is basically unplayable except in limited, where it's totally crazy if you pick up multiples.
Play it in Iname as One and when you cast your 12 mana commander and bounce it back to your hand to take advantage of its ETB ability, discard it to this thing instead. Tech!
0/2 for 3 is a pretty mediocre rate and I don't like that the ability requires you to already have an established board presence to get a genuine game-changer, but I suppose General Tazri is probably lacking in super-impactful creatures so this could work there. The only other application of this card that I can think of is Reaper King changelings, but that has the same boardstate problem and can already run more on-themehaymakers.
This set is a huge disappointment, aside from making a few cards like Gamble and the Elemental Blasts available in foil.
I also 100% thought Mirage fetches would be in this set, but I'm not super-disappointed by that like I am with Crucible.
I draw Basilisk Collar.
Blink is so busted in this format that I'm happy to play instant-speed blink-with-upside for four mana.
So yeah, this is basically unplayable except in limited, where it's totally crazy if you pick up multiples.