just a repeated routine, except for an immediate add to x: magic

{wrong}
hidden rules:
if curr[n]%26 + magic[n] == i[n]: curr[n] = 0
curr[n] = (curr[n]*26) + (i[n]+8)

requirement:
curr[last] = 0

// evidence
99998499593576 z[14] = 455
99998499594676 z[14] = 455
99998499595776 z[14] = 455
99998499596876 z[14] = 455
99998499597976 z[14] = 455

99998422592476 z[14] = 13
89998422592476 z[14] = 13
98998422592466 z[14] = 13
99987422592476 z[14] = 13
69998422592476 z[14] = 13

59998426997979 z[14] = 0
49998426997978 z[14] = 0
39998426997977 z[14] = 0

// evidence smaller
51112188486865 352
11112111481316 6461
11114332481315 248
11113232481315 248
11114332481315 248

fairy = 1, 1, 1, 1, 26, 26, 1, 1, 26, 26, 1, 26, 26, 26
magic = 13, 12, 12, 10, -11, -13, 15, 10, -2, -6, 14, 0, -15, -4
witch = 8, 13, 8, 10, 12, 1, 13, 5, 10, 3, 2, 2, 12, 7

w = in[n]
x *= 0
x += z
x %= 26
z /= fairy[n]
x += magic[n]
x = x==w ? 1 : 0
x = x==0 ? 1 : 0
y = 25
y *= x
y ++
z *= y
y = w+witch[n]
y *= x
z += y

// procedure:
w = in[n]
x = z%26 + magic[n]
z /= fairy[n]
y = 25
if x == w:
	z not modified
else:
	y = 26
	z *= 26
	z += in[n] + witch[n]

// working forwards

n = 0
x = 13
z = 9..17

n = 1
x = 9..17 + 12
z = (9..17)*26 + 14..22

n = 2
x = z%26 + 12
z = z*26 + 9..17 
  = ((9..17)*26 + 14..22)*26 + 9..17

n = 3
x = z%26 + 10
z = z*26 + 11..19
  = (((9..17)*26 + 14..22)*26 + 9..17)*26 + 11..19

n = 4
x = z%26 - 11 = 11..19 - 11 => 0..8
z /= 26 => z = 
  = ((9..17)*26 + 14..22)*26 + 9..17
if 1..9 != 0..8:
	in[4] = 9
	z = (z*26 + 21)
	  = (((9..17)*26 + 14..22)*26 + 9..17)*26 + 21
else:
	in[4] = 1..8
	z = ((9..17)*26 + 14..22)*26 + 9..17

n = 5
case in[4] == 1..8:
x = z%26 - 13 = 9..17 - 13 = -4..4
z /= 26 => z = (9..17)*26 + 14..22
if 1..9 != -4..4:
	in[5] = 5..9
	z = z*26 + 5..9 + 1
	  = ((9..17)*26 + 14..22)*26 + 6..10
else: 
	in[5] = 1..4
	z = (9..17)*26 + 14..22
case in[4] == 9:
x = z%26 - 13 = 21 - 13 = 8
z /= 26 => z = ((9..17)*26 + 14..22)*26 + 9..17
if 1..9 != 8:
	in[5] = 1..7,9
	z = z*26 + 1..7,9 + 1
	  = (((9..17)*26 + 14..22)*26 + 9..17)*26 + 2..8,10
else:
	in[5] = 8
	z = ((9..17)*26 + 14..22)*26 + 9

n = 6
case in[4] == 1..8:
case in[5] == 5..9:

case in[5] == 1..4:

case in[4] == 9: 
case in[5] == 1..7,9:
z = (((9..17)*26 + 14..22)*26 + 9..17)*26 + 2..8,10
x = z%26 + 15 = 2..8,10 + 15 > 9
z = z*26 + 1..9 + 13 = 
  = ((((9..17)*26 + 14..22)*26 + 9..17)*26 + 2..8,10)*26 + 14..22
z is too big, further down it cant be divided enough to be 0
case in[5] == 8:
	
// procedure:
w = in[n]
x = z%26 + magic[n]
z /= fairy[n]
y = 25
if x == w:
	z not modified
else:
	y = 26
	z *= 26
	z += in[n] + witch[n]

// working backwards

n = 9
x = z%26 -6
z = z/26
if in[n] != x:
	z = (z*26 + 3 + in[n])
	
	at the end z in R[10]
	if x == in[n] => z%26-6 == 1..9
		=> z%26 = 7..15
		=> S[9] = (j*26+7..15 | j in R[10])
	else
		at the end z is a multiple of 26 + 3..12
		=> T[9] = (j+3..12 | j%26 != 7..15, j in R[10])
	R[9] = S[9] + T[9]

n = 10
x = z%26 + 14
if in[n] != x:
	z = (z*26 + 2 + in[n])

	at the end z in R[11]
	if x == in[n] => z%26+14 == 1..9
		z%26 == 15..23
		but every j in R[11], j%26 = 1..9, impossible
	else
		=> z%26 = 0..14 u 24..25
		=> z = z*26 + 3..11, in R[11] if 3..9
		=> z = z*26 + 3..9
		=> R[10] = { j | j%26 != 15..23, j*26+3..9 in R[11] }

n = 11
x = z%26
z = z/26
if in[n] != x:
	z = (z*26) + 2 + in[n]

	at the end z=0 or (z=4*26..14*26, z%26=16..24) = R[12]
	at the start z=0 -> z = 2+in[n] == 0 impossible
	if x == in[n] => z%26 == in[n] 
		=> at the end z in R[12]
		=> in[n] = z%26 
		=> z%26 = 1..9
		=> z = (j+i..9 | j in R[12]*26) = R[11]
	else 
		z is a multiple of 26 + 3..11 and z in R[12]
		but every j in R[12] j%26=16..24 so z not in R[12]

n = 12
x = -15 + z%26
z = z / 26
if in[n] != x:
	z = (z*26) + 7 + in[n]

	at the end z is in 4..14
	at the start either z = 0 -> z=7+in[n] -> in[n] = 1..7
	or z in 5*26..14*26 and z%26-15 == in[n]
		so in[n] = 1..9
		so z%26 = 16..24, z=5*26..14*26
		len(R[12]) = 90

n = 13
x = -4 + z%26
z = z / 26
if in[n] != x:
	z = (z*26) + 7 + in[n]

	at the end z has to be 0
	so at the start z < 26, z-4>0, z-4<10
	so z < 26, z>4, z<14
	so in[n] = 1..9 

n = 14
z = 0



inp w
mul x 0
add x z
mod x 26
div z 1
add x 13
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 8
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 1
add x 12
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 13
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 1
add x 12
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 8
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 1
add x 10
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 10
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x -11
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 12
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x -13
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 1
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 1
add x 15
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 13
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 1
add x 10
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 5
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x -2
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 10
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x -6
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 3
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 1
add x 14
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 2
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x 0
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 2
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x -15
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 12
mul y x
add z y

inp w
mul x 0
add x z
mod x 26
div z 26
add x -4
eql x w
eql x 0
mul y 0
add y 25
mul y x
add y 1
mul z y
mul y 0
add y w
add y 7
mul y x
add z y