Doubling your mana at such a lower cost lets this deck seize an early lead and drown the table beneath massive monsters before they have a chance to react
There's a smattering of cards that specifically interact with otters or make otters, and many of them are nice, efficient cards, even for a spellslinger deck with inexplicably few otters: Lilypad Village Valley Floodcaller Harnesser of Storms Otterball Antics Pearl of Wisdom Rockface Village Splash Portal Stormchaser's Talent Valley Flamecaller All of this adds up to an Izzet Prowess deck that features otters, which is awesome
If you deal battle damage and detach a material, though, this monster deals a whopping 500 burn damage for every card in your opponents hand
Utilizing black, red, and white means Kaalia has access to almost every Demon card
Gen 34: Expansion began, with E-cards and EX sets going up to ~165
cards is simple and easy