Here's a Fatal Counter combo, Certified Mike Z Easy meaning every bit is optimized to hurt, and there is nothing simpler you can do for this much damage. Verified on all characters, no mag, no spark:
CH 2C, 2C xx AC, small step forward BSledge, keep holding forward afterward, 5B->5C->6A xx AC, EGadget = 3954. Why work super hard for 200 more damage? (^.^)'
(That bit in the middle: small step -> BSledge is easy, but you keep holding forward to walk immediately after the BSledge is over, which puts you in range to catch them before they land with 5B.)
Remember, if you want to test min damage you can do black-beat combos...6C xx AC 5 or 6 times then into super. However, it does the same dmg. :^)
Due to the new way Heat works, you get crazy amounts of super meter for everything no matter the scaling. From 70% (maybe less) meter you can do throw, BSledge, 5C->6A xx AC, 6C xx Spark, Astral.