When new cards come out, sometimes old cards get a lot better (which was most notably seen with the introduction of Link Monsters)
If I include a cycle of something like rare or uncommon two-colour lands, like the Ravnica dual lands and bouncelands, I want to post them all at once, which means they would add to the 385 in a way like 389/393 cards
Personally, I've enjoyed playing Jenova as a +1/+1 counters deck, even without many Mutants
Where new card designs always leave some uncertainty around their design intent was companion meant to be that good
The price information is based on their own marketplace sales history, so there may be little to no data for exceedingly rare cards
This combo was so powerful that it sparked an entire Legacy deck, dubbed "Scepter-Chant!" What if you want to cast an Instant that costs more than two mana every turn