I played against the same Blastoise/Keldeo in the last game of swiss and then about twenty minutes later in top cut.
I ended up having to play that matchup 3 times. (counting the top cut match as one).
I'd say your Regionals one was pretty unorthodox. More the way you played it than the actual list which only had about a four cards difference than what might be considered standard.
RE: Keldeo EX / Blastoise (With and without Black Kyurem EX)
That, in my opinion, is the sole problem with this deck.
1-2 Tropical beaches are necessary and they are almost impossible to get hold of.
Darkrai or Rayeels decks are probably the cheap and viable decks right now.
Also, I would try to get some ace spec possibly Computer Search as it would help a Darkrai deck alot.
I don't really like Ghetsis
I haven't tested it that much yet, but I think it's a little underpowered.
If it discarded the items I would consider it, but as is, I'd rather use a supporter that is more useful in setting up.
This is going to be horrible, you spend all this money on the card and then a month or so after you needed it, it goes down to almost nothing.
Happens all the time though.