Snow mana is generic by nature, but effects that would reduce a spell or ability by a generic mana do not affect Snow mana
Dawnglade Regent Wow, an 8/8 that gives all your permanents hexproof, this should be a fantastic card
Firebending Fire Lord Zuko shows us how fire can be used as energy, as it comes from the breath, not the muscle of direct damage or firebreathing
I just think the card is well executed it being an artifact plays well with Urzas Saga, Improvise and Springleaf Drum, and unlike Thalia, Guardian of Thraben where youre locked out by the tax, you have the choice with Esper Sentinel which presents interesting in-game decisions as you have to balance the tax on the mana versus providing your opponent with card advantage a similar decision to that of being on the play or on the draw
Beginners will find it tough to understand how to create the ideal conditions for the cards to shine