Even pricing in the new demand from Standard, it seems unlikely that Pyroclasm can stick at more than $20, and dropping back down towards $10 seems likely
Additionally, if an opponent would target their own permanents with beneficial effects, a player can cause Spellskite to receive these benefits instead, meaning it often must be answered as quickly as possible
A good rule of thumb is that the more resources your opponent has, the less drawing a card helps them, so if you are behind on cards this is likely worth activating
Path of Annihilation Marcy: Fairly interesting little ramp card, if a little slow in doing so, but it does sort of give you Eldrazi Convoke
Idol of Oblivion I'd normally say Idol of Oblivion should be reserved for token decks, but so many decks can produce incidental tokens these days, so the Idol probably has more homes than it might seem
In form and function, this an Amber/Sapphire all-Disney Princess deck, where each princess may help others, with stacking abilities