Max Shutter speed
Olympus E-M1 II can shoot continuously at max speed of
15.0 fps and has max shutter speed of
1/8000 sec. E-M1 II also has an electronic shutter which can shoot silently at max speed of
1/32000s. One thing to keep in mind is that electronic shutter may cause rolling shutter / jello effects, and also banding issues under artificial light on your images.
Flash
Unfortunately E-M1 II doesn't have a built-in flash but it has a flash shoe for mounting external flashes.
Focusing
Olympus E-M1 II features both Contrast Detection and Phase Detection autofocus (AF) systems which ensures speed and accuracy of focusing in most situations. The AF system has 121 points to choose from.
Olympus E-M1 II also features
Face detection AF where it intelligently detects the faces in the frame and locks the focus automatically.
Focus Stacking
Macro shooters will love Olympus E-M1 II's Focus Stacking feature. In this mode, E-M1 II automatically composites multiple shots taken at different focal positions using focus bracketing to create a single image with maximum depth of field.