Summary (nicked off Wikipedia): -
Set in Universal Century 0091, the Federation sends Amuro Ray to recruit Judau Ashta to help deal with a group of Zeon remnants. While this seems routine, the Zeons have uncovered what they call the Giant God" namely the Ideon (which is never actually called Gigantis nor Ideon within the story). While investigating, Judau learns that the Zeons are planning on using Mineva Lao Zabi's Newtype powers to awaken the Giant God and get their revenge. Unfortunately, it goes out of control and begins attacking anything in sight. As Judau infiltrates the Giant God, Amuro (along with Char Aznable) fights to distract it. Mineva Zabi controlling the Giant GodAs Judau nears Mineva, the spirit of Karala and her baby Messiah appear, explaining that Ideon remade the universe because it hoped that a new type of human - namely, Newtypes - would be the universe's salvation from war. But since this turned out not to be the case, the Giant God was set to remake the universe again. Judau also learns that he is the reincarnation of Ideon protagonist Cosmo, and violently opposes this plan. With Amuro's help, he manages to free Mineva and shut the Giant God down before it can do any more harm, and it is destroyed.
The manga is non-canon apparently, and while I've still to get around to watching past the first few episodes of Gundam ZZ, it's not really a clean fit with Ideon - notably the Giant God being deactivated on an asteroid rather than blown apart as seen in 'Be Invoked'. But then I can't read Japanese, so maybe they address that. The more stylised design of the Ideon is interesting, though, and it's great to see a few things dusted down - for an unashamed Ideon fanboy like myself, the sight of a number of Zeon mobile suits getting wiped out by the All-Directional Missile Attack is a great one. Tow, the scans here aren't mine - they were scanned by Join. Whether Join is a him, a her or a them I don't know; I'm eternally grateful and hope I'm not putting anyone out by uploading them.