EOS 7D Mark II: built-in flash Stroboscopic mode

The EOS 7D Mark II built-in flash allows you to shoot stroboscopic multi flash without external Speedlites. If you plan on doing this, you will find the maximum power of your flash is not as high as in normal shooting. In fact, the maximum flash power you can set is quarter power. This is because the flash needs to fire several times and does not have time to recycle fully between each burst. If you need more flash power, then you should use additional Speedlites in a multiple flash setup.
Camera settings
EOS 7D Mark II