Lets say the Rabblemaster player has some pressure on the battlefield already, potentially a Tarmogoyf, and each turn that passes allows them to get in for damage at a rate that is unacceptable to the Terminate player
For example, Skyward Spider's primary color pair would be white-blue
(Even though, again, this list is not about power
His core strength lies in repeatable card draw tied to opponent behavior
Basically, at any given rarity (and considering the era of the card in question), we must compare its current price to other cards at the same rarity (and ideally set) that have already peaked more than the others
A couple years ago that would have been cute text, but now we have real contenders especially with our first card mentioned and the Overlords from Duskmourne