The requirement of eight different names among unlocked doors translates to just four fully unlocked Room cards, which is a lot more attainable than it might first appear
Any creature that comes under your control has summoning sickness the turn you obtain control of it, even if it was a non-creature permanent before becoming a creature (thats why even vehicle commanders have summoning sickness, too)
Orcish Bowmasters Damage and tokens in one place Orcish Bowmasters is a two-mana Black 1/1 with flash
Some are rare by virtue of what they were in, perhaps an underprinted Secret Lair, like the Galaxy Staples
I love the fact that we're just implementing Mono Red Prison in Vintage with a lot of the same technology, but also that Ragavan just adds a huge aggro element to the deck as well
Ba Sing Se Ba Sing Se, from Avatar: The Last Airbender , is a green utility land that enters untapped if you control a basic land (something a budget mana base can usually accomplish) and has earthbend 2: You turn one of your lands into a hasty creature with two +1/+1 counters, and it returns tapped if it dies/exiled