Using Technique Rune and Double-Beat Rune in Tandem (bug)

[serogane]

I noticed this bug today and did some additional testing. It seems that it requires a few conditions to trigger:

1. The character obviously must have both runes equipped.
2. The character's normal attack must hit twice (like Nanami or Riou). I tried with someone like Jowy and it didn't work.
3. Both the normal attack and the subsequent "double-beat" attack must land on the same enemy.
3a. The enemy must have enough HP to survive your first normal attack or the subsequent double-beat attack won't have the chance to trigger (obvious but important).
3b. The character can't* attack more than the intended enemy during the normal attack phase (i.e. the character is too fast and ends up hitting multiple enemies in the normal attack phase).
4. Potch must be stolen during the "double-beat" attack phase.
4a. 3 things can happen pertaining to the technique rune on your weapon: i) you steal on the normal attack phase, ii) you steal on the double-beat attack phase or iii) you fail to steal.

When all these conditions are met, the numerical damage values from the double-beat attack will actually not show up on screen (only the amount of potch stolen will appear on screen). However, the game seems to register the damage as having been done to the enemy.

For example:

Sickle has 70HP. Nanami deals 19+19=38 damage to Sickle during the normal attack phase. Nanami "hits" Sickle again during the double-beat attack phase and steals 200 potch (but no damage values show up). Sickle dies anyway. Going by the amount of damage Nanami did during the normal attack phase (i.e. 38 points), it's likely she dealt 38 points of damage again during the double-beat attack phase.

So 38+38=76 damage=dead Sickle.

Is this a known bug?

*I haven't verified if the bug can still trigger under such circumstances so if you do find out please let me know. <- Verified to be false.

Update:

- This bug shows up even when you critical on the double-beat attack phase, assuming the above conditions are met
- It looks like the bug can also occur during the normal attack phase

For example:
a) character deals the killing blow to enemy A
b) character also steals potch from enemy A (killing blow damage from part a) is hidden and only potch stolen is shown) <- bug
c) character moves on directly to attack enemy B

- uh I'll try to explain what I just saw:

a) During normal attack phase, Nanami first attacks enemy A
b) Nanami then moves on to attack enemy B
c) During double-beat attack phase, Nanami first attacks enemy B
d) Nanami then moves on to attack enemy A, kills enemy A and successfully steals potch (bug triggered)

It looks like condition 3b. above has been proven false.

[BadPotato]

Sound like a minor graphical glitch, but the fact that a killing blow might trigger it even on a normal attack might suggest that there might be other kind of disorder in the battle animation.

If you conbine these attack with poison/fire/daze/... rune while doing a killing blow, maybe there's more animation skipped.