Control of the Shrine Maiden of Hakurei and Marisa Kirisame, instigating conflict amongst several people (including vampires, onis, and a half-ghost), throwing the whole country into chaos, and attempting to destroy the Hakurei Barrier which would inevitably destroy gensokyo...
My only nitpicks would be that we never saw what Seiga used to force Youmu to work for her, that Yuka never did anything and that outside of Ran & Chen never saw the reactions of everyone else involved