you need the yellow sign i bet you watching of my mugen videos
activate basara mode the A (engun/assist) B ( Activate Basara mode) C (Y+Z charge attack)
press that B button to activate that basara mode make sure you need that yellow sign
to trigger their Basara skill
if you know how their trigger those 2 specials (ex. phantom dive and hell dragon) its pretty simple combine those commands then hit the z button ( special 2 , special 1 arrow commands) + z (strong attack)
and voila you tirggered their OHKO skill