; ---- everything before this same as first variety.  as is -------
; ---- everything through next dotted line, but just shown for context. --------

lda $3ef8,x     ; status byte 3
pha
lda $3ee5,x     ; status byte 2
pha

LDA $3330,X
XBA 
LDA $331D,X     ; A.top=blocked status byte 3, A.btm=blocked status #2
REP #$20        ; Set 16-bit Accumulator

EOR #$FFFF      ; make it so blocked statuses = 1, and vulnerable statuses = 0.
                ;  i find this more intuitive to work with, and it doesn't take
                ;  any more bytes overall.  will toggle back later.
 
STA $EE         ; starting list of intended blocked statuses, bytes 2 and 3.
LDA $3C6C,X     ; monster/equip status bytes 2-3
AND #$EE78      ; Dance, Stop, Sleep, Condemned, Near Fatal, Image will all be 0
sta $eb         ; save would-be permanent statuses

and $01,s       ; if any of these are also possessed...
tsb $ee         ; ...add them to list of intended blockages

; ------- changes start here ----------

lda $ee
trb $eb         ; would_be_perm AND NOT(blocked) AND NOT(would_be_perm AND had)

pla             ; retrieve possessed statuses, bytes 2 and 3
and $ee         ; ((would_be_perm AND had) OR blocked) AND had
                ;  = (would_be_perm AND had) OR (blocked AND had)
tsb $eb         ; (would_be_perm AND NOT(blocked) AND NOT(would_be_perm AND had))
                ;  OR ((blocked AND had) OR (would_be_perm AND had))
                ; wtf is that?!  it actually simplifies to the intended:
                ; (had AND blocked) OR (would_be_perm AND NOT(blocked))
                ; i can't prove that without a ton of lines, so verify with a
                ;  truth table.  okay, two tips for the curious.  show that:
                ;   1. (a AND NOT(b) AND NOT(c)) OR (x OR c) =
                ;      (a AND NOT(b)) OR (x OR c)
                ;   2. (would_be_perm AND NOT(blocked)) OR (blocked AND had)
                ;      already contains a (would_be_perm AND had).
                ; more straightforward yet longer code would have a "STA $F0"
                ;  (or whatever free variable) right after the above "STA $EE",
                ;  then use $F0 instead of $EE for the two modifications to $EB.
                ; anyway, Variable $EB is our mirror-status-immunity inducers

; 43 bytes for this chunk

jsr add_mirrors ; need to move the below or above instruction into this function
                ;  for space reasons.  move the one with the one-line comment!

lda $ee         ; get list of intended blocked statuses (bytes 2 and 3)

; ------- everything after this same as in first variety, but likely --------
; ------- shifted forward 2 bytes. ------------