To determine the total cost of a spell, start with the mana cost or alternative cost you're paying (such as a flashback cost), add any cost increases (such as kicker costs), then apply any cost reductions (such as that of The Wind Crystal's first ability)
As long as your devotion to red is less than five, Purphoros isn't a creature
They serve to give your side of the board tempo by allowing your creatures to attack (removing defenders), giving you more time to set up the board (removing attackers/expensive creatures), and allow for combat tricks (saving your creatures after damage is on the stack
Then when you swing you toss a +1/+1 counter on any dork and then double them
Its definitely a subtheme at best, but its pretty powerful when you can assemble it
Learn more Getting to know the best blue cards MTG has to offer is an absolute must if youre a big brain player who wants to win by stopping your opponents game plan dead in its tracks via tricky outplays or drawing half your library in one turn