Mulligans
General Mulligans
These cards arent a hundred percent needed and can easily be replace by spellstone, corpse raiser or even moat lurker works. This deck has a lot of flexibility as you can try with Cairn or Baron Riverdaire.
Combo Mulligans
Spiritsinger Umbra is quite powerful and makes an insane combo with carnivorous cube, combo's especially well with white eyes you shuffle a lot of storm guardian into your deck. The reason Emperor is in the deck is because the deck cost is quite expensive and will allow you get out the death rattle combos out quicker.
Control Mulligans
These are all quite important to have if you want survive aggressive decks, healing wave is better then healing rain as your almost guarantied the full 14 heal as you have a lot of expensive heals.
A really fun deck that actually do quite well in wild ladder. Its just generally a lot of fun to play and definitely recommend giving this deck a go.
Double portail, double storm, double volcano ????
yep, ur power is in the late game, so you need the tools to survive until then