Rune Sword half strength (display only):

08028520  2811 cmp r0, #0x11
08028522  d10f bne $08028544
08028524  1c22 add r2, r4, #0x0
08028526  325a add r2, #0x5a
08028528  2014 mov r0, #0x14
0802852a  5620 ldrh r0, [r4, r0]
0802852c  0fc1 lsr r1, r0, #0x1f
0802852e  1840 add r0, r0, r1
08028530  1040 asr r0, r0, #0x01
08028532  8811 ldrh r1, [r2, #0x0]
08028534  1a08 sub r0, r1, r0

Rune Sword null crit (display only):

08028536  2100 mov r1, #0x0
08028538  8010 strh r0, [r2, #0x0]
0802853a  1c20 add r0, r4, #0x0
0802853c  3066 add r0, #0x66
0802853e  8001 strh r1, [r0, #0x0]
08028540  3004 add r0, #0x4
08028542  8001 strh r1, [r0, #0x0]

Some other compare function (seems to do nothing):

080288e6  2811 cmp r0, #0x11
080288e8  d018 beq $0802891c
080288ea  2811 cmp r0, #0x11
080288ec  dc04 bgt $080288f8
080288ee  2810 cmp r0, #0x10
080288f0  d009 beq $08028906

080288f8 2899 cmp r0, #0x99
080288fa d111 bne $08028920

Half damage check:

08028f06  2810 cmp r0, #0x10
08028f08  db38 blt $08028f7c
08028f0a  2811 cmp r0, #0x11
08028f0c  dd01 ble $08028f12
08028f0e  2899 cmp r0, #0x99
08028f10  d134 bne $08028f7c

Ranged animation at close range check:

08052d58  2811 cmp r0, #0x11
08052d5a  d104 bne $08052d66

Legendary weapons have special BGM and white flash:

080533be  2884 cmp r0, #0x84
080533c0  d010 beq $080533e4
080533c2  1c20 add r0, r4, #0x0
080533c4  f7c3 bl $080171b4
080533c8  2885 cmp r0, #0x85
080533ca  d00b beq $080533e4
080533cc  1c20 add r0, r4, #0x0
080533ce  f7c3 bl $080171b4
080533d2  2886 cmp r0, #0x86
080533d4  d006 beq $080533e4
080533d6  1c28 add r0, r5, #0x0
080533d8  f7c3 bl $080171b4
080533dc  283c cmp r0, #0x3c
080533de  d001 beq $080533e4
080533e0  2000 mov r0, #0x0 ;This 0 means no special BGM
080533e2  e000 b $080533e6
080533e4  2001 mov r0, #0x1 ;This 1 means there is a special BGM
080533e6  bc30 pop {r4,r5}
080533e8  bc02 pop {r1}
080533ea  4708 bx r1
