<!-- Research receipt: original investigation notes. File references below refer to paths inside the downloadable evidence archive. Later findings supersede explicitly earlier scope statements. -->

# Red Venom: Venom Rush kick extension

Stock Euro 980123 `mvsc.zip`, unchanged code. This diagnostic sets the
**pre-match selected character fixture** at `$FF40B0` to `$24` while the game
is preparing the match. It does not reproduce the secret character-selection
code. It does not overwrite live move state or character ID. The game starts
the selected fighter normally; QCF+LK activates the move via ordinary inputs.
Health, meter and positions are seeded before saving; each input variant
restores that same saved state. Both players are human-controlled.

QCF+K enters `+$E6=$04`, dispatching to `$067F2E`: **Venom Rush**. The
screenshots show Red Venom producing the ground tendril attacks.

## Code path

- In the eligible animation window, `$068024` reads new button edges `+$D4`
  and `$068028` ORs them into the buffer at `+$398`.
- At the animation boundary, `$068030` merges current edges, the `+$DE`
  input buffer, and `+$398`.
- `$06803C` masks with `$0700`: **kick buttons only**.
- An accepted kick increments the byte loop counter `+$50` at `$068042`
  and clears the buffers at `$068048`/`$06804C`.
- The normal boundary code decrements that counter at `$068062`.
- With no new repeat credit, the counter becomes negative and the move
  enters its ending animation. With a credit, `$06806C`–`$068078` loads
  another attack animation instead.

This is a windowed repeat mechanism, not damage multiplication. Buffered
button bits are a yes/no condition at a boundary: pressing three kicks at once
does not grant three repeats. More attacks need not all connect, because the
defender can leave the tendrils' path.

## Paired results

Each trial begins with the same QCF+LK. Extra input starts after that command.
Kick or punch taps alternate pressed/neutral callbacks. Direction input
rotates through cardinals with neutral between. Extra inputs stop at
observation 360. Counts below are the native combo counter during the first
move only, not a universal move hit total.

| Extra input | Maximum native combo | First move exits |
| --- | ---: | ---: |
| None | 2 | 47 |
| Hold all kick buttons | 4 | 61 |
| Tap all kick buttons | 7 | 391 |
| Tap all punch buttons | 2 | 47 |
| Rotate directions | 2 | 47 |

Holding all kicks creates one new MK/HK edge after the LK command, which buys
one repeat. It does not sustain the move. Kick tapping takes the accepted
repeat branch 28 times (writes observed at `$068042` and the buffer-clear
instructions), versus zero for no-input, punch-tap, and direction trials.
Those repetitions greatly extend the attack even though only some attacks
remain connected to the defender.

`qcf_k.csv`, `qcf_k.log`, screenshots and `summary.json` record this run.
`probe.lua` records all fixture interventions explicitly.

## Ordinary Venom control

The same harness selecting ordinary Venom ID `$0C` produced QCF+K selector
`$04` as expected. All five input variants produced two native hits and exited
at observation 80. Defender HP was 131 except the direction trial's 132. This
supports the distinction between Red Venom's repeatable Venom Rush and the
ordinary version. The control's independent saved fixture is in
`ordinary_control/`; compare input variants within each saved fixture.
