diff --git a/Makefile b/Makefile
index 233f3c7d..6392fabb 100644
--- a/Makefile
+++ b/Makefile
@@ -83,7 +83,7 @@ NODEP := 1
 endif
 
 #$(C_BUILDDIR)/need_interworking_file_name.o: CFLAGS += -mthumb-interwork
-$(C_BUILDDIR)/code_080B1520.o: CFLAGS += -mthumb-interwork
+$(C_BUILDDIR)/code_080B1520.o: CFLAGS = -O1 -mthumb-interwork -Wimplicit -Wparentheses -Werror -Wno-multichar
 
 C_SRCS := $(wildcard $(C_SUBDIR)/*.c $(C_SUBDIR)/*/*.c)
 C_OBJS := $(patsubst $(C_SUBDIR)/%.c,$(C_BUILDDIR)/%.o,$(C_SRCS))
diff --git a/asm/code_080B1520.s b/asm/code_080B1520.s
index 0400faab..99a98729 100644
--- a/asm/code_080B1520.s
+++ b/asm/code_080B1520.s
@@ -5,99 +5,6 @@
 
 	.text
 
-	thumb_func_start sub_080B15E8
-sub_080B15E8: @ 0x080B15E8
-	push {r4, r5, r6, lr}
-	sub sp, #0x88
-	adds r5, r1, #0
-	lsls r0, r0, #0x10
-	lsrs r3, r0, #0x10
-	ldr r0, _080B1600 @ =gUnk_02036A50
-	ldr r0, [r0]
-	ldrh r0, [r0, #4]
-	cmp r3, r0
-	blo _080B1608
-	ldr r0, _080B1604 @ =0x000080FF
-	b _080B168A
-	.align 2, 0
-_080B1600: .4byte gUnk_02036A50
-_080B1604: .4byte 0x000080FF
-_080B1608:
-	ldr r0, _080B1694 @ =gUnk_02036A50
-	adds r6, r0, #0
-	ldr r0, [r0]
-	ldrb r1, [r0, #8]
-	lsls r0, r1, #1
-	mov r4, sp
-	adds r2, r0, r4
-	adds r2, #2
-	movs r4, #0
-	cmp r4, r1
-	bhs _080B1632
-_080B161E:
-	strh r3, [r2]
-	subs r2, #2
-	lsrs r3, r3, #1
-	adds r0, r4, #1
-	lsls r0, r0, #0x18
-	lsrs r4, r0, #0x18
-	ldr r0, [r6]
-	ldrb r0, [r0, #8]
-	cmp r4, r0
-	blo _080B161E
-_080B1632:
-	movs r0, #1
-	strh r0, [r2]
-	subs r2, #2
-	strh r0, [r2]
-	movs r4, #0xd0
-	lsls r4, r4, #0x14
-	ldr r0, _080B1694 @ =gUnk_02036A50
-	ldr r0, [r0]
-	ldrb r2, [r0, #8]
-	adds r2, #3
-	mov r0, sp
-	adds r1, r4, #0
-	bl sub_080B1568
-	adds r0, r4, #0
-	mov r1, sp
-	movs r2, #0x44
-	bl sub_080B1568
-	add r2, sp, #8
-	adds r5, #6
-	movs r4, #0
-	movs r6, #1
-_080B1660:
-	movs r1, #0
-	movs r3, #0
-_080B1664:
-	lsls r1, r1, #0x11
-	ldrh r0, [r2]
-	ands r0, r6
-	lsrs r1, r1, #0x10
-	orrs r1, r0
-	adds r2, #2
-	adds r0, r3, #1
-	lsls r0, r0, #0x18
-	lsrs r3, r0, #0x18
-	cmp r3, #0xf
-	bls _080B1664
-	strh r1, [r5]
-	subs r5, #2
-	adds r0, r4, #1
-	lsls r0, r0, #0x18
-	lsrs r4, r0, #0x18
-	cmp r4, #3
-	bls _080B1660
-	movs r0, #0
-_080B168A:
-	add sp, #0x88
-	pop {r4, r5, r6}
-	pop {r1}
-	bx r1
-	.align 2, 0
-_080B1694: .4byte gUnk_02036A50
-
 	thumb_func_start sub_080B1698
 sub_080B1698: @ 0x080B1698
 	push {lr}
diff --git a/src/code_080B1520.c b/src/code_080B1520.c
index 989efe66..c86d10bc 100644
--- a/src/code_080B1520.c
+++ b/src/code_080B1520.c
@@ -1,8 +1,17 @@
 #include "global.h"
 
-extern u16 (*gUnk_02036A50)[];
-extern u16 gUnk_08DE7D40[];
-extern u16 gUnk_08DE7D4C[];
+typedef struct struct_08DE7D40 {
+    u16 unk_00;
+    u16 unk_02;
+    u16 unk_04;
+    u16 unk_06;
+    u8 unk_08;
+    u8 filler[3];
+} struct_08DE7D40;
+
+extern struct_08DE7D40* gUnk_02036A50;
+extern struct_08DE7D40 gUnk_08DE7D40;
+extern struct_08DE7D40 gUnk_08DE7D4C;
 
 u32 sub_080B1520(u16 unk_1) {
     u32 ret;
@@ -21,22 +30,20 @@ u32 sub_080B1520(u16 unk_1) {
     return ret;
 }
 
-NONMATCH("asm/non_matching/code_080B1520/sub_080B1568.inc", void sub_080B1568(u32 unk_1, u32 unk_2, u32 unk_3)) {
+NONMATCH("asm/non_matching/code_080B1520/sub_080B1568.inc", void sub_080B1568(u16* src, u16* dest, u32 cnt)) {
     u32 temp;
 
     u16 u1;
     u16 IME_save;
-    u16* ptr;
 
-    u1 = unk_3;
+    u1 = cnt;
     IME_save = REG_IME;
     REG_IME = 0;
     temp = REG_WAITCNT & 0xf8ff;
-    ptr = *gUnk_02036A50;
-    temp |= ptr[3];
+    temp |= gUnk_02036A50->unk_06;
     REG_WAITCNT = temp;
-    REG_DMA3SAD = unk_1;
-    REG_DMA3DAD = unk_2;
+    REG_DMA3SAD = (u32)src;
+    REG_DMA3DAD = (u32)dest;
     REG_DMA3CNT = u1 | 0x80000000;
     if ((REG_DMA3CNT_H & 0x8000) != 0) {
         while ((REG_DMA3CNT_H & 0x8000) != 0) {}
@@ -44,3 +51,38 @@ NONMATCH("asm/non_matching/code_080B1520/sub_080B1568.inc", void sub_080B1568(u3
     REG_IME = IME_save;
 }
 END_NONMATCH
+
+u32 sub_080B15E8(u16 unk_1, u16* unk_2) {
+    u16 stack[0x44];
+
+    u16* ptr;
+    u8 t1, t2;
+    u16 value;
+
+    if (unk_1 >= gUnk_02036A50->unk_04) {
+        return 0x80ff;
+    } else {
+        ptr = stack;
+        (u8*)ptr += (gUnk_02036A50->unk_08 << 1) + 1;
+        ((u8*)ptr)++;
+        for (t1 = 0; t1 < gUnk_02036A50->unk_08; t1++) {
+            *(ptr--) = unk_1;
+            unk_1 >>= 1;
+        }
+        *(ptr--) = 1;
+        *ptr = 1;
+        sub_080B1568(stack, (u16*)0xd000000, gUnk_02036A50->unk_08 + 3);
+        sub_080B1568((u16*)0xd000000, stack, 0x44);
+        ptr = stack + 4;
+        unk_2 += 3;
+        for (t1 = 0; t1 < 4; t1++) {
+            value = 0;
+            for (t2 = 0; t2 < 0x10; t2++) {
+                value <<= 1;
+                value |= (*ptr++) & 1;
+            }
+            *(unk_2--) = value;
+        }
+        return 0;
+    }
+}