ehi i dont know if i saw it bad but does it combo ? c.B , nj D , DM ? and in the case it would be , , ?
and is it possible to activate HD after f.B or after c.B , B , HD , f.B or none of those is possible ?
There are a couple shortcuts: you can do d.B, qcf x2, up+D, back C.
Or I find easier:d.B, qcf, up+D, hcb C (so your one was close).
I'm pretty sure Leona's command move f.B does NOT activate because she is in the air (although air normals do) much like Chin's df.B or df.D which you can't BC off of either. We'll double check for you (Ash's b.B seems to be an exception).
d.B, d.BC (time it like a chain), into whatever works.
Alternatively: d.b x2, cancel into d~u+ABC... works as well.