PCB Marisa B Shot and Exploit Explanation

Author: sp0

Basic mechanics

Unlike all other shot types that operate on a simple 30-frame shot cycle, Marisa B’s laser shots are further dependent on option position and have some additional unique behaviors.

A screenshot of MarisaB being unfocused — Figure 1: This is the unfocused position. If player is shooting and no unfocused lasers are active, new unfocused lasers spawn. When player stops shooting OR enters focusing state, unfocused lasers enter the fading state and linger for 30 frames (0.5 second).

A screenshot of MarisaB focusing — Figure 2: This is the focusing position. When the options are moving between focused and unfocused positions, neither unfocused laser nor focused laser can spawn.

A screenshot of MarisaB being focused — Figure 3: This is the focused position. If player is shooting, focused laser spawns. When player stops shooting OR enters focusing state (by releasing focus), the laser immediately deactivates.

The “player is shooting” condition follows the same 30-frame shot cycle rule as other shot types, i.e. releasing shoot does not stop shooting immediately, until the current 30-frame cycle ends. This means that pressing shoot once while unfocused will make unfocused lasers appear for 1 second (0.5s active shooting and 0.5s fading).

Focus-mashing supershot exploit

The fading unfocused lasers do not count as active but still deal damage. If player returns to unfocused state before the old lasers fade away, multiple copies of unfocused lasers can stack. With very fast and short tapping, the unfocused laser damage output can be boosted to an insane level.
As previously mentioned, options must stay in the unfocused position to shoot new lasers. This means the time spent unfocusing MUST be longer than the time spent focusing, otherwise options will be stuck at focusing state and no lasers are created at all. Optimal TAS uses 20hz 1f focus (2f uf, 1f f cycle) which produces 10X damage(!!!) from unfocused lasers. RTA runs can reach around 10hz tapping, still good for 5X laser damage increase, although with certain conditions (explained later). Normally, unfocused lasers deal 6 damage each every 2 frames. TAS shooting reaches a constant 60 damage per frame just from lasers (note that damage cap is 70 per frame) for 3,720 dps combined with main shot, almost as high as MoF MariBug damage. RTA-viable mashing can still get 1,800 dps from lasers (assuming constant 10hz tapping for 30 damage per frame), 2,280 dps combined with main shot. In comparison, Reimu B close range unfocused shot (ordinarily best in the game) only deals ~1,550 dps.
PND’s site gives a 2 star rating for Marisa B’s Cherry+ gain rate during boss invincibility (which is extremely important for scoring) while the max is 5 stars for Reimu B and Marisa A. With the exploit however, a fair rating for Marisa B will be somewhere around 9 stars (LOL)

How it is actually performed

It is (probably) physically impossible to mash shift with one hand while holding Z for shooting (remember that the taps have to be short enough to make options return to unfocused position). However, in classic touhou games (EoSD-IN) left and right shift are considered the same input, therefore you can use some hypertapping technique on the right shift key with right hand to reliably reach ~10hz while keeping the inputs shorter than 2f to make the exploit work. This does mean you lose the ability to move while doing so. However, in a majority of cases, you do not need to move during boss invincibility period as the bullet pattern hasn’t expanded yet. In other cases where you are allowed to temporarily not move (for example Lily White in stage 4) this trick can also be extremely useful.
It is perhaps possible to hypertap shift and Z together to make the exploit useful while moving, but my mashing with left hand is not nearly as good and will often hold shift for too long, and consequently lose all laser damage. (If you are interested, you can try doing this yourself. Maybe you can be good at it if you are leftie or ambidextrous.)
There should be no dispute on the RTA validity of this trick since the vanilla game accepts right shift input and no additional key mapping is required. However, performing the said trick on a controller is most likely physically impossible, since most players use the back button for focusing. Using an alternative configuration such as A/B buttons for focus makes normal gameplay uncomfortable, and you will still need at least an alternative grip to be able to mash fast enough. Thus unfortunately, controller players will likely be at an extreme disadvantage in this category.

Effect in scoring

Marisa B can now mostly follow the strong shot route (base route template of Reimu B/Marisa A), with some compromises due to her bomb being less effective for cancels. The route I’m currently using skips the stage 5 suicide and does an intentional border break on Lyrica non 2. However, with her unique advantage on stage 4, Marisa B is still good enough to tie Marisa A in score potential.

The current WR pace will be completely irrelevant on a good run. Projected pace looks similar to my Reimu B PB, entering stage 4 at around 50 million behind (365m/695k if without mistakes) and following close afterwards (the potential difference in stage 5 covered by mistakes in my PB run). An ideal run can reach low to mid 3.4b range.

Thank you for checking out the guide written by sp0 !