Pretty simple,
Use secrets to control the game and get some damage off when you can.
Honestly, secret decks are troll and this one has been winning a lot.
I say simple but you really need to know the deck you are against and plan for the big swings. Try to bluff a secret to keep a secret on the board and draw out your opponents cards when they dont really want to play them.
Stack up Arcane Bolts for potential big damage with Aegwynn spell damage boost.
Dont worry about making a big play with Orion. Do what you can with it but dont hinge your game on making it work. Its too easy to take him out of the game. Just throw him out there when it feels kinda safe and see what happens.
I think this is the final edit. Currently at Diamond 7 with this deck and its getting dubs so, might keep running it to see if I can get to Legend. Im actually seeing quite a few people running secret mage.
Hope you like it and have fun!