diff --git a/backend/routes/admin.js b/backend/routes/admin.js
index 047f6d2..1c89234 100644
--- a/backend/routes/admin.js
+++ b/backend/routes/admin.js
@@ -1,7 +1,7 @@
 import { Router } from 'express';
 import multer from 'multer';
 import { Image, Menu } from '../models/index.js';
-import { convertAndUpload, deleteFromS3 } from '../services/image.js';
+import { convertAndUpload, safeDelete } from '../services/image.js';
 import { getPublicUrl } from '../lib/s3.js';
 import { sequelize } from '../lib/db.js';
 import bossCrystalRouter from './admin/boss-crystal.js';
@@ -165,13 +165,7 @@ router.post('/images/delete', async (req, res) => {
   try {
     const images = await Image.findAll({ where: { id: ids } });
 
-    await Promise.all(
-      images.map((img) =>
-        deleteFromS3(img.path).catch((err) =>
-          console.warn(`S3 삭제 실패 (${img.path}):`, err.message)
-        )
-      )
-    );
+    await Promise.all(images.map((img) => safeDelete(img.path)));
     await Image.destroy({ where: { id: ids } });
 
     res.json({ success: true, deleted: images.length });
diff --git a/backend/routes/admin/boss-crystal.js b/backend/routes/admin/boss-crystal.js
index 3c4764c..c3ec330 100644
--- a/backend/routes/admin/boss-crystal.js
+++ b/backend/routes/admin/boss-crystal.js
@@ -1,7 +1,10 @@
 import { Router } from 'express';
 import multer from 'multer';
 import { BossCrystalBoss, BossCrystalBossDifficulty } from '../../models/index.js';
-import { uploadBossImage, deleteBossImage } from '../../services/boss-crystal/image.js';
+import { convertAndUploadTo, safeDelete } from '../../services/image.js';
+
+const BOSS_IMAGE_PREFIX = 'crystal/boss';
+const bossImagePath = (name) => `${BOSS_IMAGE_PREFIX}/${name}.webp`;
 import { getPublicUrl } from '../../lib/s3.js';
 import { sequelize } from '../../lib/db.js';
 import { UPLOAD_FILE_SIZE_LIMIT, PARTY_SIZE, DIFFICULTIES } from '../../constants.js';
@@ -101,7 +104,7 @@ router.post('/bosses', upload.single('image'), async (req, res) => {
     if (existing) return res.status(400).json({ error: '같은 이름의 보스가 이미 존재합니다' });
 
     // 이미지 업로드
-    const imagePath = await uploadBossImage(req.file.buffer, trimmedName);
+    const { path: imagePath } = await convertAndUploadTo(req.file.buffer, bossImagePath(trimmedName));
 
     // 마지막 정렬 순서
     const max = await BossCrystalBoss.max('sort_order') || 0;
@@ -155,15 +158,14 @@ router.patch('/bosses/:id', upload.single('image'), async (req, res) => {
     // 새 이미지 업로드 또는 이름 변경 시 이미지 재업로드
     if (req.file) {
       const oldPath = boss.image_path;
-      newImagePath = await uploadBossImage(req.file.buffer, newName);
+      const uploaded = await convertAndUploadTo(req.file.buffer, bossImagePath(newName));
+      newImagePath = uploaded.path;
       if (oldPath && oldPath !== newImagePath) {
-        await deleteBossImage(oldPath);
+        await safeDelete(oldPath);
       }
     } else if (newName !== boss.name && boss.image_path) {
-      // 이름만 변경 - 기존 이미지를 새 경로로 복사하는 대신 이름 기반 경로 업데이트
-      // 간단하게 처리: 기존 키를 새 키로 교체할 수 없으니, 이미지가 없으면 그대로, 있으면 path만 갱신
-      newImagePath = `crystal/boss/${newName}.webp`;
-      // 실제로 이름이 바뀌면 이미지를 다시 올려달라고 하는 게 안전. 현재는 path만 업데이트하고 추후 다음 업로드 시 새 경로로 저장됨
+      // 이름 변경 시 path만 갱신 (실제 파일은 다음 이미지 업로드 때 새 경로로 저장됨)
+      newImagePath = bossImagePath(newName);
     }
 
     await sequelize.transaction(async (tx) => {
@@ -196,7 +198,7 @@ router.delete('/bosses/:id', async (req, res) => {
     if (!boss) return res.status(404).json({ error: '보스를 찾을 수 없습니다' });
 
     if (boss.image_path) {
-      await deleteBossImage(boss.image_path);
+      await safeDelete(boss.image_path);
     }
     await boss.destroy();
     res.json({ success: true });
diff --git a/backend/routes/admin/symbol.js b/backend/routes/admin/symbol.js
index bac5273..290b9e8 100644
--- a/backend/routes/admin/symbol.js
+++ b/backend/routes/admin/symbol.js
@@ -1,7 +1,7 @@
 import { Router } from 'express';
 import multer from 'multer';
 import { Symbol, SymbolLevel } from '../../models/index.js';
-import { convertAndUploadTo, deleteFromS3 } from '../../services/image.js';
+import { convertAndUploadTo, safeDelete } from '../../services/image.js';
 import { getPublicUrl } from '../../lib/s3.js';
 import { sequelize } from '../../lib/db.js';
 import { UPLOAD_FILE_SIZE_LIMIT, SYMBOL_MASTER_LEVEL } from '../../constants.js';
@@ -167,7 +167,7 @@ router.patch('/symbols/:id', upload.single('image'), async (req, res) => {
       imageKey = imagePath(basic.type, basic.region);
       await convertAndUploadTo(req.file.buffer, imageKey);
       if (row.image && row.image !== imageKey) {
-        try { await deleteFromS3(row.image); } catch { /* ignore */ }
+        await safeDelete(row.image);
       }
     } else if (basic.type !== row.type || basic.region !== row.region) {
       // 이름/종류 변경 시 새 경로로 rename 대체 불가 → 기존 키 유지
@@ -211,7 +211,7 @@ router.delete('/symbols/:id', async (req, res) => {
     if (!row) return res.status(404).json({ error: '심볼을 찾을 수 없습니다' });
     const key = row.image;
     await row.destroy();
-    if (key) { try { await deleteFromS3(key); } catch { /* ignore */ } }
+    if (key) await safeDelete(key);
     res.json({ success: true });
   } catch (err) {
     console.error('심볼 삭제 오류:', err.message);
diff --git a/backend/services/boss-crystal/image.js b/backend/services/boss-crystal/image.js
deleted file mode 100644
index f382c77..0000000
--- a/backend/services/boss-crystal/image.js
+++ /dev/null
@@ -1,26 +0,0 @@
-import sharp from 'sharp';
-import { uploadObject, deleteObject } from '../../lib/s3.js';
-
-const BOSS_IMAGE_PREFIX = 'crystal/boss';
-
-/**
- * 보스 이미지를 webp로 변환하고 RustFS의 crystal/boss/{name}.webp에 업로드
- * @param {Buffer} buffer
- * @param {string} bossName
- * @returns {Promise<string>} S3 키 (예: crystal/boss/검은마법사.webp)
- */
-export async function uploadBossImage(buffer, bossName) {
-  const webp = await sharp(buffer).webp({ quality: 90 }).toBuffer();
-  const path = `${BOSS_IMAGE_PREFIX}/${bossName}.webp`;
-  await uploadObject(path, webp, 'image/webp');
-  return path;
-}
-
-export async function deleteBossImage(path) {
-  if (!path) return;
-  try {
-    await deleteObject(path);
-  } catch (err) {
-    console.warn(`보스 이미지 삭제 실패 (${path}):`, err.message);
-  }
-}
diff --git a/backend/services/image.js b/backend/services/image.js
index b620ffb..83e4025 100644
--- a/backend/services/image.js
+++ b/backend/services/image.js
@@ -30,6 +30,16 @@ export async function deleteFromS3(path) {
   await deleteObject(path);
 }
 
+// 삭제 실패해도 흐름을 끊지 않는 버전 (이전 이미지 정리 등에 사용)
+export async function safeDelete(path) {
+  if (!path) return;
+  try {
+    await deleteObject(path);
+  } catch (err) {
+    console.warn(`S3 삭제 실패 (${path}):`, err.message);
+  }
+}
+
 /**
  * 지정한 경로로 webp 변환 후 업로드 (덮어쓰기)
  * @param {Buffer} buffer - 원본 이미지 버퍼