Mulligans
General Mulligans
shimmerfly is a strong turn 1 play that generates spells
secret plan is the only other play this deck can make on turn 1 (never waste your rapid fire), and you could potentially discover a snipe or something useful to play on turn 2
Electrowright is nearly always a 3 mana 4/4, which is very strong in the early game. If you see this in your opening hand along with a 5+ cost spell, you may want to keep the expensive spell to activate this
Violet spellsword is one of the defining cards in this deck and almost always has extremely good stats (5/6 or 6/6). Playing this card on turn 4 gives you a huge advantage in tempo
Animal companion is another great turn 3 tempo play if you are missing electrowright, and is powerful versus both control and aggro decks. Also it is nice to cast early so when you play zuljin you can cast it again
Aggro Mulligans
Against aggro, mull for these cards along with the other 5 in the general section.
Explosive trap is very strong against token/flood decks
wing blast is great board clear for larger minions and has a good chance of costing 1
This deck uses a lot of powerful hunter spells to summon strong minions and clear the board, while gaining very good tempo with violet spellsword, electrowright, and sunreaver warmage. Against control decks, this deck wins by draining their board clears and playing zuljin to gain tempo, value, and a slightly better hero power. Veressa windrunner is also a strong win condition, but watch out for weapon removal. You would want to run this deck over the current spell hunter because it is much better against aggressive decks and is strong against both mage and hunter, arguably the 2 best classes right now.