Bahamut you can't miss as he's open anytime.
Phoenix on the other hand I recall is miss-able depending on your actions in a certain flashback.
EDIT: Alrighty, I have no joined the ranks of the completed. Did all of the rift and void today.
But first Bahamut.
Now who is this handsome devil?
X-Death was no match for my party of non-mimes and/or freelancers.
