Blistercoil Weird does not have summoning sickness.
Sorcerer Class is at least level two.
Steps
Activate Blistercoil Weird by tapping it, adding ({U} magic symbol) that can only be spent to cast an instant or sorcery spell, or to gain a Class level.
Cast Mystic Speculaiton with buyback by paying ({U} magic symbol) .
Blistercoil Weird triggers, and Sorcerer Class's third ability triggers if it it level three.
Resolve the Blistercoil Weird trigger, giving itself +1/+1 until end of turn and untapping it.
Resolve the Sorcerer Class trigger, if applicable, dealing damage to each opponent equal to the number of instants and sorceries you've cast this turn.
Resolve Mystic Speculation, causing you to scry 3 and return Mystic Speculation to your hand.
Repeat.
Results
Infinite damage.
Infinitely large Blistercoil Weird until end of turn.