So, I'm running a Multiplayer Melek, Izzet Paragon in my LGS. The deck is just for fun, a lot of storm spells to go comboing and doing chaos on the table, but i'm preocupied about leaving the table too soon (i'm playin againts some heavy aggro, like the New Marchesa, and a fast deck, like Purphoros). To prevent this for happening, i'm currently running 7 creatures (besides Melek), are they: [[Goblin Electromancer]], [[Guttersnipe]], [[Talrand, Sky Summoner]], [[Hypersonic Dragon]], [[Charmbreaker Devils]], [[Psychosis Crawler]] and [[Dack's Duplicate]].

Besides that, i'm running a bunch of spells that steal, copy and create tokens to mantain the board presence.
In your experience, how many creatures is enought to have some board presence without break the "storm" concept of the deck?