Snap Crackle Boom (Legacy)

Nice boom deck. Designed to be unassuming and annoying, until it cracks off like a dickens and blows the opponent up in 1 or 2 hits
Every card is under 4 mana.
The main engine is Veyran, Voice of Duality and/or as many Harmonic Prodigy cards you can squeeze onto the board as possible, to win by amplifying the number of times casting an instant or sorcery activates a permanent's abilities.
Has multiple win and support strategies, depending on the draw that game: Firemind's Research, Sorcerer Class, Aria of Flame, Rod of Absorption, Poppet Stitcher, and Young Pyromancer.
The more engine pieces you have on the board, the bigger the explosions, and there are plenty of little ways to mess with your opponent while enabling yourself - Betrayal is your best friend in this deck - use it to tax anything they have that needs to tap, and get yourself some draw.
Ideally this deck is played as aggressive control as you constantly take out their creatures while building up your direct damage through your engine. Sneaky and destructive, flexible.

Fourth deck.

My usual opponent is a computer scientist that likes playing midrange non-interaction/high synergy decks, and this deck counters his best deck (mono-white healing), which was meta on Arena and at the upper tiers, until just recently.

Polishing

*Will add Curse of Bloodletting if I decide to break the 3 mana rule for this deck