Mono-Blue can not ramp up its mana very well and requires extensive use of mana rocks, so Mana Drain adding the mana helps you to start ramping up into your big spells
Izzet Guildgate plays well to the futuristic and industrial side of Magic: The Gathering , revealing how machinery can be just as awe-inspiring as the fantastical
I'll tell you what I look for in a processed card too
"[Type]cycling [cost]" means "[Cost], Discard this card: Search your library for a [type] card, reveal it, put it into your hand, then shuffle." This type is usually a subtype (as in "Mountaincycling") but can be any card type, subtype, supertype, or combination thereof (as in "basic landcycling")
Losing this planeswalker strikes a blow against white decks, especially Azorius control, who as we'll see later, loses another corker of a card
For example, the black enchantment Black Market Connections provides a nice source of mana, card draw, and tokens with Changeling that will benefit from the Sliver horde's bonus
