Getting a creature from any graveyard each turn is a huge benefit for you, and youll know you have a couple of your opponents creatures to choose from thanks to this card forcing them to sacrifice a few
Enchantment tutors are the bread and butter of a shrine deck, and since everything you want to find is an enchantment, Idyllic Tutor and Enlightened Tutor are perfect
Ob Nixilis, Captive Kingpin turns increments of one damage into counters and Impulse draw, creating an infinite pinging loop with Casey Jones
He isn't as big a threat as people though, but he is still an excellent Grixis (red/blue/black) Commander
Depending on the type, each set will normally have its own theme, either based around a particular fictional setting in the lore, or perhaps tailored to one particular mode of play, like the Commander or Modern formats