Aromatic Mist
Sensuble
Mercury would like to have a fews words with you. You didn't even notice the planet closest to the sun.
But seriously, I do like like this idea for the most part. It sort of reminds me of Mega Man V (not 5 but V).
They could also base some legendaries of famous constellations (although Cresselia already is reminiscent of Cygnus). That sort of reminds me of the Mega Man Star Force series.
Damn you Mega Man, you have all these different games, yet nothing new is going to come out for you.
The saddest thing is, I knew I was skipping something :v
For Mercury I'd say Poison, in reference to the element, and maybe Dark because Mercury was seen as a God of Thieves? But he wasn't exactly evil (