Shock is already great, and this will become a better Lightning Bolt in the late for many decks in the format
Green had enormous, powerful creatures, but was not very proficient at making sure you drew them
Kefka, Court Mage // Kefka, Ruler of Ruin is also a standout
At GP Barcelona in 2019, during the Hogaak Summer, I was playing Hogaak against Eldrazi Tron on Day Two and my opponent opened with a Leyline of the Void and Grafdiggers Cage on turn one, on the play
They often come with the downside of giving your opponents a bunch of cards, but you can mitigate that by ensuring you have more mana or ways to punish your opponents for drawing cards
This means that in every two-color combination, you should be able to find a least six really strong MDFCs, and if you reach down into the "often play" category, you should be able to find eight or nine that are worth putting in your deck