The basic formula for Sektor's combos is this:
(1, 2, B1), A, TU, B2, Flame
(1, 2, B1), A, TU, B, TU, Up Missile
(1, 2, B1), A, TU, B, EXTU, B2, Flame
(1, 2, B1), A, TU, B, EXTU, JK, TU, Up Missile
Basically A can be JK / F4, 3 / B3, 4 while B is a different string (can be the same as A but doesn't get the highest damage). If you end with TU (I've seen SwiftTomHanks do this), you can use an Up Missile safely after it. After EXTU you can end with Up Missile or 1, Up Missile.
These are his highest damaging combos off of each string: (I recorded the damage pre-patch so that's why I didn't include it)
The three 45% 1 meter BnBs:
1, 2, B1, JK, TU, F4, 3, EXTU, B2, Flame
1, 2, B1, F4, 3, TU, B3, 4, EXTU, B2, Flame
1, 2, B1, F4, 3, TU, JK, EXTU, B2, Flame
Left Lift 1 Meter Combos:
B3, 4, TU, F4, 3, EXTU, B2, Flame
U3, 4, TU, F4, 3, EXTU, B2, Flame
Other 1 Meter Combos:
F4, 3, TU, JK, EXTU, B2, Flame
2, 1, TU, F4, 4, EXTU, B2, Flame
B2, TU, F4, 4, EXTU, B2, Flame
Teleport Punisher Combos: (It's better to wait until the opponent lands then go for a full combo punish)
F4, dash, F4, 3, TU, B3, 4, EXTU, B2, Flame
F4, 3, TU, F4, 3, EXTU, B2, Flame
Wall Combos:
1, 2, B1, back dash, B2, 1, 1, 2, 2, Up Missile
1, 2, B1, back dash, B2, 1, 1, 2, 1, 2, 2, Flame
1, 2, B1, F4, back dash, B2, 1, 1, 2, 2, Flame
1, 2, B1, back dash, B2, 1, 1, 2, B2, 1, 1, 2, Flame (Not a BnB)
1, 2, B1, JK, EXTU, B2, 1, 1, 2, 2, Flame (Situational, not a BnB)
(Escape from wall combo) B2, TU, B2, 1, B2, 1, 1, 2, 2, Flame (Not a BnB)
Advanced 1 Meter Combos: (None of these are BnBs)
B2, TU, B2, 1, B3, 4, EXTU, B2, Flame
^^First B2 can be replaced with 2, 1 / F4 / B3, 4
1, 2, B1, (Instant Air) TU, B2, 1, B3, 4, EXTU, B2, Flame
X-Ray Combos:
1, 2, B1, JK, TU, B2, X-Ray
1, 2, B1, F4, 3, TU, dash, 1, 2, X-Ray
B2, TU, B2, 1, dash, 1, 2, X-Ray
1, 2, B1, (Instant Air) TU, B2, 1, dash, 1, 2, X-Ray (Not a BnB)
(Wall Combo) 1, 2, B1, F4, back dash, B2, 1, 1, 2, 2, X-Ray