Returning any artifact from the graveyard to the top of your library for a simple investment of 2 mana (plus tapping the Ruins) is heady stuff
Myriad is just a plain powerful ability, and being able to catch up in multiple ways by hitting different players is pretty effective and aggressive
Having a lot of tapped lands sucks, but hitting your colors and drawing gas is worth the loss of tempo
Wizards has expanded the concept to include broader special treatments like alternate art, textured foils, borderless frames, anime-style illustrations, and etched finishes
Thats a lot of hoops to jump through just to get a legend onto the field, but at least it lasts until your next turn, so cards like Jin-Gitaxias, Progress Tyrant have a whole round to punish your opponents before they revert back to whatever they were
It reduces the mana cost of creature spells of the chosen type by 1 and gives you a chance at the beginning of your upkeep to look at the top card of your library and draw it if its a creature of the chosen type