I did something similar to this a while back. I used Scourge of Valkas to turn all the tokens Broodmother produced into burn spells.Also Utvara Hellkite might help, turn all your 1/1s into 6/6s just by attacking with them :)

Yeah I contimplated both of those. Xenagos, God of Revels replaced Scourge of Valkas as a cheaper game winner, once the dragons start to show up it is basically game. And the idea behind Utvara Hellkite is good, but he is so expensive to hard cast I am almost relying on Elvish Piper to get him out, which sucks. The ramp is there sure, but there is only so much room in the deck.

Basically both of those just add insult to injury when it comes to Dragon Broodmother she ends games on her own. Its like here I have 2 10/10 flying dragons...now you take 4 damaged for my 4 dragons being in play...and then when they attack I get 4 6/6 dragons, who then deal a ton more damage by entering and thats game. Amazing combo, but its kind of a shot in the dark to get them all in play.

Doubling Season is pricier than Parallel Lives (in-game and out), but would do twice the work here since it would also double the amount of counters you'd be putting on with devour.

Also, it would allow Sarkhan Vol to immediately crush face. Missed that. Too funny.

yeah that is pretty crazy... didn't think about Doubling Season with planeswalkers. if i get my hands on a pair of them for whatever reason they will be a great addition.