Cool idea, man, I love it!

I have a few suggestions, but I'd like to know what your budget is first, as that will allow me to suggest relevant things accordingly.

Budget doesn't matter. Spent already too much money on magic, so there is no turning back now :-)

Shweet. Rakdos Aggro really isn't my thing, but herewego:

Have you considered abusing the (in my opinion) criminally underplayed power of Nova Chaser? It seems like a T2 Nova Chaser is totally possible in this deck.

Ex: T1, Flamekin Brawler (important, because it doesn't die to Heartless Summoning).

T2, Heartless Summoning.

T3: Priest of Urabrask for 1, giving you a total of 5 mana, drop 1 for Mass Hysteria (I highly doubt any creature they put out will be bigger or more aggressive than yours, so it's a net gain for you.) and drop 2 for Nova Chaser, champion flamkin brawler, swing for 9 trample. Spend the other 2 perhaps on... Hellrider, for even more aggro?

Great filler cards for this deck would be things like Flamekin Harbinger, to ensure you hit your chasers, or Thunderblust perhaps. Scorchwalker is a pretty sexy bloodrush. Heartless Summoning is great, but if you wanted to get rid of it for some reason, Smokebraider is pretty sexy, as is Generator Servant.

...I kinda wanna make an elemental tribal now xD

Also: All of my suggestions wound up being super budget. Hue.

That's an interesting suggestion, really, but it drives a bit off of the way I was planning to play this deck. Hellrider is actually a good idea.

However, I personally don't like Flamekin Brawler just for Nova Chaser, eventhough Nova Chaser is a great card.

Mass Hysteria: Nice, didn't know that card, I will consider it.

I thought about Generator Servant, but Heartless Summoning just seems stronger in this deck.

Thunderblust will never have trample (if persist goes off, he will die due to Heartless Summoning), so it's a no for him too.

Thanks for your suggestions!

yeah, I realized that as I was typing it, sorry :x