Hearthpwn

No big synergy here - just a bunch of strong Standard cards that push decks around.  Pen Flinger might seem like an oddball choice but notice the six one-drop spells plus the spells that can be generated from Magescribe; that's a lot of pings!  The top-end cards are extremely oppressive: free spells (likely clutch removal) from a 4/9 body, Kel'Thuzad, a Troublemaker, Grommash and OG Alexstrazsa.

The deck's main weakness is having very little AoE, so if someone pops off with a ludicrous wipe-your-whole-board-and-develop-20-stats turn (granted it's Swingstone but not often quite that swingy) it likely can't come back from that.  To play around it as much as possible board presence will be key - even on an empty board Scalerider should still be played, and even if it can't trigger spellburst that turn Magescribe should still be played.  The weapons should be assertively played out as well and lategame should go face if opponents aren't contesting the board; this deck can play out games awhile but not for as long as bona fide control decks.