Some meterless corner combos i found:
12xdf4, b32, b32, s4xdf2. Deals 35% dmg.
12xdf4, b32, b32, 22xdf2. Deals 36% dmg.
B2, b2, b1xdf4, micro dash, 22xdf2. Deals 34% dmg.
f122xdf4, b32, b32, s4xdf2. Deals 38% dmg (jesus...).
Meterless midscreen combos:
12xdf4, b32, b32, micro dash, 22xdb3...