Lebia (A.C.'s trio of hyper-AIs), Fate, Dee, possibly A.C. herself. Trigon I'm not quite as sure about, as he could just be a bored asshole with a codebreaker set. But he's certainly on the list of potentials. 
Mr. Fnord interdimensional man of mystery
FenWiki - Your One-Stop Shop for Fenspace Information
"I. Drink. Your. NERDRAGE!"

Mr. Fnord interdimensional man of mystery
FenWiki - Your One-Stop Shop for Fenspace Information
"I. Drink. Your. NERDRAGE!"