As I am reading part 3 of IDW Megatron's Origins, I am still confused. Is that the beginning of the war? or the war still going when the series started? I mean is there anything before that? like maybe in Dreamwave?
Dreamwave's stories have NOTHING to do with IDW's. Megatron Origins is the start of the war. I really don't see how anyone can come to any other conclusion. Yeah, there's a few odd stories/flashbacks to before then, but that's when the fight started.
Megatron Origin is indeed depicting the beginnings of the Autobot-Decepticon conflict, though it doesn't really escalate into a full-blown war until the 'Autocracy' miniseries. Several other IDW stories have flashbacks set before Megatron Origin, but MO is the chronologically earliest series set entirely in the past.
It's the beginning of the Great War story more than actual Megatron story. Title is quite misleading. If you want more complete Megs origin you need to combine M:O and Chaos Theory.
In order, the first appearance of Megatron chronologically is in Chaos theory, the first appearance of Decepticons is in Shadowplay, then Megatron Origins.
So if I follow the IDW's chronological order, I see Spotlight Orion Pax. But I don't think I've seen it in the IDW collection, is it a stand alone comic?
Stand alone, collected in Dark Prelude. That takes place after Megatron Origins but before Autocracy.
If you're intending to read the issues in chronological order, I can't recommend enough that you DONT. They've spent a lot of time doing flashback issues or setting parts of plot lines in the distant past in order to build up a massive payoff in the "present" reading them chronologically is bizzare and spoils whole plots. Im bias, but I'd recommend this: http://www.tfw2005.com/boards/trans...03136-idw-transformers-g1-reading-orders.html
