so ive been blasting jeff loomis's new album for like the past month and my favorite song is probably the ultimatum.

It has an amazing mix of all out shred and melodic phrasing.

My favorite part is the "chorus" i guess you can call it.
http://www.youtube.com/watch?v=CNoFS1d9fcY
You can check it out at 1:15, but i would recommend listening to the whole song (or album, or loomis/nevermore discography if you haven't), and i really like that bluesy type phrasing mixed in with those diminished/augmented runs over a chord progression that's not really a "bluesy" chord progression,

My question is, what theory goes into creating chord progressions that can serve bluesy riffs plus blazing diminished arpeggios at the same time?

I haven't checked yet but I'm willing to bet he used harmonic minor

I think diminished sometimes sounds very good over the minor ii or vi chord in a bluesy setting.
1-b3-b5 IT fits perfectly.

The dim7 sounds even better to me over the ii.
You can think of it as a combination of the dorian and blues scales.

1-b3-b5-6

The constant min3rd interval of a dim7 also gives you a nice 2note per string pattern you can use and since it's a constant min3rd interval you can "start" it behind the root if you like which gives a different feel.

examples of a 6 note dim7 run over Amin (functioning as a ii chord)

----------------
----------------
----------------
----------7h10--
------6h9-------
--5h8----------- or

----------------
----------------
-------------5--
--------4h7-----
----3h6---------
--5-------------

Can't really say it sounded that bluesey to me but that's just my opinion.

My advice having studied Paul's playing over the last5/6 years is to just learn it all and figure it out yourself, what sounds like what and why. It's too easy for me to explain in 6 paragraphs why Paul does certain things and how it gives him a certain sound but that doesn't mean someone reading it will be able to do it or even understand it. I know it's not the straight forward answer you'd want but it's not a straight forward solution.

Holy crap it's, Mitch. Sup, man? Are you on Facebook? I made a group for the long-time RX members to keep in touch there.

Hey! I logged in the other day as I lost the site from my favourites so it was out of habit so I thought why not. Yeah I'm on FB, just put in Mitch DuCran and there should be a pic of a motorcycle, white & red.

I think I only have Lamer on there..

But I don't have facebook

Don't you? Who the hell am I thinking of then haha!

Ermmm, I dunno then purhaps I'm thinking of someone on the COB forum...

Can't find ya, Mitch. Do you have a link to your page? I don't think you can add me if we don't have a common friend so I have to add you.

Try this
http://www.facebook.com/#!/mitch.ducran

Thanks, Mitch

Accepted you all.

Good to hear from ya, man. Kinda tough to keep track of people nowadays.