Some are rare by virtue of what they were in, perhaps an underprinted Secret Lair, like the Galaxy Staples
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)
Newer titles have moved away from the paradigm of the heroes of light collecting the scattered crystals in favor of broader, more convoluted plot-lines, but most games in the series still have a crystalline element somewhere
Locking out artifact mana, Chromatic Spheres, Expedition Maps, Engineered Explosives, Aether Vial, equipment, Oblivion Stone, and more, Collector Ouphe really is just a 2/2 Stony Silence
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