In the Second Wave scenario, where exactly can a power from the first wave be used? What if the power is targeted from a Sacred Site? What about (one of many weird exception cases)?
The power can target any land or Spirit it normally could – no current Spirit needs to have a Sacred Site (or Presence in a land of the correct terrain, etc.) The power is being "played" by the Spirit from the prior game – if it cares about the originating land, or where the Spirit has Presence / Sacred Sites, it can assume that for purposes of targeting and resolution the Spirit has up to 2 Presence in each land. The Power can't affect the playing Spirit (which is not in the game). Technically, Energy/other costs can't be paid, but it's more fun if you say that costs up to 8 Energy / 4 Time, can be paid. (Or rough equivalent, so "Elemental Teachings" can grant 3 of any element(s), "Draw Towards a Consuming Void" could redo its effects once, etc).