diff --git a/cogs/book.py b/cogs/book.py
index 8f8f7ad..7a1ae40 100644
--- a/cogs/book.py
+++ b/cogs/book.py
@@ -48,10 +48,17 @@ async def book(self, ctx, type, *target):
             db_ailie.disconnect()
             return
 
-        target = " ".join(target)
-        exists = False
-        hero_name = ""
-        hero_stats = hero_buffs = hero_skill = hero_on_hit = hero_on_normal = {}
+        if target:
+            target = " ".join(target)
+            exists = False
+            hero_name = ""
+            hero_stats = (
+                hero_buffs
+            ) = hero_skill = hero_on_hit = hero_on_normal = {}
+        else:
+            await ctx.send("No hero or equipment mentioned.")
+            db_ailie.disconnect()
+            return
 
         if type in ["heroes", "hero", "h"]:
             exists = True
diff --git a/cogs/bot.py b/cogs/bot.py
index 874592d..ed08f9c 100644
--- a/cogs/bot.py
+++ b/cogs/bot.py
@@ -131,14 +131,18 @@ async def feedback(self, ctx, *feedback):
 
         db_ailie.disconnect()
 
-        # Process complain
-        feedback = " ".join(feedback)
-        await self.notifyOwner(ctx, feedback, "agree")
+        if feedback:
+            # Process complain
+            feedback = " ".join(feedback)
+            await self.notifyOwner(ctx, feedback, "agree")
 
-        # Mimic loading animation
-        await ctx.send(
-            f"Ding dong, <@{ctx.author.id}>! " + "Your message has been logged."
-        )
+            # Mimic loading animation
+            await ctx.send(
+                f"Ding dong, <@{ctx.author.id}>! "
+                + "Your message has been logged."
+            )
+        else:
+            await ctx.send("Can't send anything since you put no messages!")
 
     # Send error message upon spamming commands
     @commands.Cog.listener()
diff --git a/cogs/pvp.py b/cogs/pvp.py
index 4d123d0..063993b 100644
--- a/cogs/pvp.py
+++ b/cogs/pvp.py
@@ -788,8 +788,7 @@ def confirm_application(message):
                 return
         except Exception:
             await ctx.send(
-                "Looks like your challenge got ignored, "
-                + f"<@{guardian_id}>. Ouch!"
+                "Looks like the challenge got ignored. Ouch!"
             )
             db_ailie.disconnect()
             return