Torpor Orb stays in the sideboard. It only stops abilities that trigger when creatures enter, and their landfall triggers (Sazh's Chocobo, Mightform Harmonizer, Earthbender Ascension, Icetill Explorer's mill) come from lands entering, so it does nothing to them. Mossborn Hydra's enters-with-a-counter is a replacement effect rather than a trigger, so Torpor Orb doesn't stop that either. Flashfreeze is the better bring-in: their threats and ramp spells are green, so it counters them cleanly at two mana. Day of Black Sun sweeps their early mana creatures and hydras cheaply since most of their threats have low mana value. Spell Snare whiffs badly since very few of their spells cost exactly 2, and We Say Thee Nay! is too slow against a deck that just wants to resolve threats and attack, so we swap them for cleaner answers.