A print of Raichu cards was reportedly made by mistake, and all but a few were destroyed
Since then, he seems to have been demoted in the lore, and he may not even inhabit the same area as the Pradesh anymore (as if he ever really knew much about them)
It is either Jund, Sultai or Golgari and has discard and self mill to empower getting value from the bin
Its impact was felt in Standard as it was included in Solar Flare decks, and in Legacy, it was a strong choice for Dredge/Reanimator strategies
The 2U mana cost is actually the same as the one blue one generic cost on the printed card - this is just how costs were formatted in Gamma
Every single Magic set fleshes out impulse draws, and casting spells from the graveyard was broken before we got a cost reducer