A very similar interaction is that if you use Shadow Madness on a Wild Pyromancer, the Wild Pyromancer triggers and damages everything. That won't work for Mana Addict because the wording is different.
Oh jeez, don't remind me. I was 7-2 in arena, and had a 2/1 Argent Protector, 3/1 Pyromancer, 4/1 Darkscale Healer, and 3/3 Ironfur Grizzly against an empty board and 2 cards in hand. Pretty nice board position, I was fairly certain he didn't have Holy Nova.
Drops Northshire Cleric. Heals Pyromancer to draw a card. Shadow Madness on Pyromancer, which triggers Pyro, killing everything but Grizzly, then runs the Pyro into the Grizzly. Completely killed my momentum. 2 turns later he dropped Ragnaros, and I was never able to deal with it.
Also, if you're interested in getting a little more fun out of arena, you can try building deliberately aggro decks. I got the idea from
http://ihearthu.com/welcome-to-the-arena-a-different-perspective/, decided to try it out with Warlock. Proceed to get the most ridiculously aggressive deck. 2 Soulfires, 1 Power Overwhelming, 1 Arcane Golem, 1 Doomguard, 1 Hellfire for fast damage. Six one drops (none of them Flame Imp unfortunately), 2 Shattered Sun Clerics, a Dark Iron Dwarf, a Defender of Argus, and 2 Dire Wolf Alphas (which are actually really good when you almost always have a 1 drop out.)
So far it's 5-0 and I've won before turn 7 three times.
I think making a strategy like this has a lot more variance in the draft phase, because your curve shifts down a lot and you don't have as many neutral 1 drops to choose from to make the deck work. Plus, it feels Warlock specific, as they're the only class that can build back quickly after board clear.