These don't have any variation from the above listed Common through Mythic scheme but are rarer cards to acquire, especially the Masterpiece cards
Gatway Shade can get especially vicious in a three color or more deck by using Gate lands instead of relying on a mono-black backdrop
Killing your opponent by letting them draw too many cards is so deliciously backwards that this archetype has been a popular rogue deck ever since, graduating to Modern with cards like Fevered Visions and Runeflare Trap
You can look at it as pseudo-card draw, where you get to target the card you will draw, but with the condition that it needs to be a card already on board for you and which can be banished in a challenge
Mystical Archives style Mystical Archives has a very specific vibe: spellbook, illuminated manuscript, fancy wizard stationery
Gold sets in general have power thats usually concentrated in tri-color rares and mythics, so this time, the best cards will be concentrated on the higher rarities a bit more