As probably mentioned, while this card is good, I don't think that it is EDH worthy, simply because if an opponent had the chance to resolve a con sphinx, you lose.

Con sphinx says that you may draw 2 cards anytime someone draws one. Of course it is a may trigger so you can just choose not to draw 2 so your opponent doesnt draw 2 (because the additional draws from con sphinx would go over to the opponent instead of you). Unfortunately, if they DO choose to draw 2, you are FORCED to draw 2 in their stead. Which of course means 2 more triggers for Con sphinx, which loops into the option for your opponent to mill you out. It costs the con phinx player no cards and force draws the opponent into oblivion, alongside having extra triggers (since each forced draw causes 2 triggers on con sphinx) giving the opponent the option to draw 2x cards where x is any number they want.

Basically, it is too risky to play in edh when all blue decks have a card that makes you lose if it resolves while y... (see all)