no matter if the walker is "aggro" ( Ajani, Caller of the Pride) they will still stall the board a bit and "gain you life"
The earliest expansions up to Homelands didnt have any rare cards and were packaged in 8-card boosters with six commons and two uncommons
We want the Masterpiece Series to make different groups happy
The most obvious slot here is something like Tortured Existence, as a way to get extra creatures and speed up your creature churn a little bit in the process
You can get your Rakdos discard triggers to kill with Megrim
Muldrotha works best with cheap permanents, especially ones that are sacrificed as part of their activation costs: Pernicious Deed becomes a repeatable board wipe, Mystic Remora is downright broken when you never need to pay for its cumulative upkeep, Caustic Caterpillar keeps blowing up stuff, and so on