Left side petras without c-dash. This one has much more consistent doubles and get more soul than right side, it overall saves about 0.5-0.8 on avg to right side (If you don't do safety wings before 2fbs, if you do it relatively breaks even).
The first petra is little bit harder but its key to delay the dash before the fireball in order to get the double. I tried to see if using any other entering movement and none of them worked that well. The monarch wings before the second petras fireballs isn't needed but highly reccomended for more consistnet doubles and to kill the close petra.
5