Svella, Ice Shaper

In some unusual cases, the order of your library will matter as you cast the spell from among the revealed cards. Remember that looking at the top cards of your library doesn’t change their order or allow you to change their order. You don’t put the cards on the bottom of your library until after you are done casting the spell.

You’ll put the cards you didn’t cast on the bottom of your library before the spell you cast resolves.

The Kaldheim set doesn’t have any cards with mana costs that include {S}, but some previous sets do. If an effect says such a spell costs {1} less to cast, that reduction doesn’t apply to any {S} costs. This is also true for activated abilities that include {S} in their activation costs and effects that reduce those costs.

If you cast a spell using Svella’s ability, you do so as part of the resolution of that ability. You can’t wait to cast it later in the turn. Timing permissions based on the card’s type are ignored.

The {S} symbol is a generic mana symbol. It represents a cost that can be paid by one mana that was produced by a snow source. That mana can be any color or colorless.

Snow is a supertype, not a card type. It has no rules meaning or function by itself, but spells and abilities may refer to it.