The easiest path to get this achievement is to go into Story Realm 1 and farm good alignment points through diplomacy & Free City Vassalage. Clear your immediate surroundings normally but you may want to wait on some of the stacks until you're stronger so you can spare the stacks for good alignment points. Settle any city ruins and build all your research buildings while Sundren keeps Yaka busy, bumrush to the Nature aligned Dragon Tome, hardswap to Order aligned tomes until you can pick up the Order tome with Ascended Warriors. Build a Dragon of each type (get a couple Golden while you're still good just in case), then betray Sundren and pillage as many improvements as you can to swing evil to get the Obsidian Dragon.