Pick Ciel
Throw keys after flaming keys after EX keys after flaming keys. While you are in the air!
Throw some more when you land; 214AB when they try to jump at you and the 214BAAB-'loop' when they just block to get free circuit for some more EX key spam.
5AAA6AAA236C combo for (almost) free and fast >3k damage if you don't know better combos.
Her AAD looks cool; use it.
22B also is great when they jump at you, as it is unblockable in the air.
22A (into 22C) on wakeup; usually works when your enemy is mashing 2A or some very slow stuff.
Always do an airthrow when you superjump. Mash the throw button if you see them doing something to shield it and do the throw.
If your opponent is a newbie, 6236[C] him on wakeup für some lulz. Flaming keys are always very fun to use, too.
ALWAYS double/tripple EX Hiero when you are in max (unles the first one is blocked), because most people tend to tech out of them.
2B is THE move. Use it in every situation. 4C is also nice sometimes.
Bunker canceling into EX Keys is very easy to do and does over 3k damage.
Enjoy winning.