diff --git a/src/server/game/Entities/Creature/Creature.cpp b/src/server/game/Entities/Creature/Creature.cpp
index 815644e689a4d3..6842bc4a41187b 100644
--- a/src/server/game/Entities/Creature/Creature.cpp
+++ b/src/server/game/Entities/Creature/Creature.cpp
@@ -264,7 +264,7 @@ Creature::Creature(): Unit(), MovableMapObject(), m_groupLootTimer(0), lootingGr
     m_spawnId(0), m_equipmentId(0), m_originalEquipmentId(0), m_alreadyCallForHelp(false), m_AlreadyCallAssistance(false),
     m_AlreadySearchedAssistance(false), m_regenHealth(true), m_regenPower(true), m_AI_locked(false), m_meleeDamageSchoolMask(SPELL_SCHOOL_MASK_NORMAL), m_originalEntry(0), _gossipMenuId(0), m_moveInLineOfSightDisabled(false), m_moveInLineOfSightStrictlyDisabled(false),
     m_homePosition(), m_transportHomePosition(), m_creatureInfo(nullptr), m_creatureData(nullptr), m_detectionDistance(20.0f),_sparringPct(0.0f), m_waypointID(0), m_path_id(0), m_formation(nullptr), m_lastLeashExtensionTime(nullptr),
-    _isMissingSwimmingFlagOutOfCombat(false), m_assistanceTimer(0), _playerDamageReq(0), _damagedByPlayer(false), _isCombatMovementAllowed(true)
+    _isMissingSwimmingFlagOutOfCombat(false), m_assistanceTimer(0), _playerDamageReq(0), _damagedByPlayer(false), _highestPlayerAttackerLevel(0), _isCombatMovementAllowed(true)
 {
     m_regenTimer = CREATURE_REGEN_INTERVAL;
     m_valuesCount = UNIT_END;
@@ -3713,7 +3713,7 @@ bool Creature::IsDamageEnoughForLootingAndReward() const
     return m_creatureInfo->HasFlagsExtra(CREATURE_FLAG_EXTRA_NO_PLAYER_DAMAGE_REQ) || (_playerDamageReq == 0 && _damagedByPlayer);
 }
 
-void Creature::LowerPlayerDamageReq(uint32 unDamage, bool damagedByPlayer /*= true*/)
+void Creature::LowerPlayerDamageReq(uint32 unDamage, bool damagedByPlayer /*= true*/, uint8 attackerLevel /*= 0*/)
 {
     if (_playerDamageReq)
         _playerDamageReq > unDamage ? _playerDamageReq -= unDamage : _playerDamageReq = 0;
@@ -3722,12 +3722,16 @@ void Creature::LowerPlayerDamageReq(uint32 unDamage, bool damagedByPlayer /*= tr
     {
         _damagedByPlayer = damagedByPlayer;
     }
+
+    if (attackerLevel > _highestPlayerAttackerLevel)
+        _highestPlayerAttackerLevel = attackerLevel;
 }
 
 void Creature::ResetPlayerDamageReq()
 {
     _playerDamageReq = GetHealth() / 2;
     _damagedByPlayer = false;
+    _highestPlayerAttackerLevel = 0;
 }
 
 uint32 Creature::GetPlayerDamageReq() const
diff --git a/src/server/game/Entities/Creature/Creature.h b/src/server/game/Entities/Creature/Creature.h
index 0669d6e4573e5a..de50e452a5b13d 100644
--- a/src/server/game/Entities/Creature/Creature.h
+++ b/src/server/game/Entities/Creature/Creature.h
@@ -369,9 +369,10 @@ class Creature : public Unit, public GridObject<Creature>, public MovableMapObje
     void SetLootRewardDisabled(bool disable) { DisableLootReward = disable; }
     [[nodiscard]] bool IsLootRewardDisabled() const { return DisableLootReward; }
     [[nodiscard]] bool IsDamageEnoughForLootingAndReward() const;
-    void LowerPlayerDamageReq(uint32 unDamage, bool damagedByPlayer = true);
+    void LowerPlayerDamageReq(uint32 unDamage, bool damagedByPlayer = true, uint8 attackerLevel = 0);
     void ResetPlayerDamageReq();
     [[nodiscard]] uint32 GetPlayerDamageReq() const;
+    [[nodiscard]] uint8 GetHighestPlayerAttackerLevel() const { return _highestPlayerAttackerLevel; }
 
     [[nodiscard]] uint32 GetOriginalEntry() const { return m_originalEntry; }
     void SetOriginalEntry(uint32 entry) { m_originalEntry = entry; }
@@ -539,6 +540,7 @@ class Creature : public Unit, public GridObject<Creature>, public MovableMapObje
 
     uint32 _playerDamageReq;
     bool _damagedByPlayer;
+    uint8 _highestPlayerAttackerLevel;
     bool _isCombatMovementAllowed;
 };
 
diff --git a/src/server/game/Entities/Player/KillRewarder.cpp b/src/server/game/Entities/Player/KillRewarder.cpp
index 78d24b4dbc5ede..b52d5c708ed722 100644
--- a/src/server/game/Entities/Player/KillRewarder.cpp
+++ b/src/server/game/Entities/Player/KillRewarder.cpp
@@ -16,6 +16,7 @@
  */
 
 #include "KillRewarder.h"
+#include "Creature.h"
 #include "Formulas.h"
 #include "Group.h"
 #include "Pet.h"
@@ -160,6 +161,27 @@ void KillRewarder::_RewardXP(Player* player, float rate)
         else
             xp = 0;
     }
+    else if (Creature* creature = _victim->ToCreature())
+    {
+        // If an ungrouped helper attacked this creature and the mob
+        // is gray for that helper, reduce XP — consistent with the
+        // group formula (half XP when a gray-level member is present).
+        // If an ungrouped higher-level player helped kill this creature,
+        // apply group-like XP scaling: level ratio + gray penalty.
+        uint8 highestLevel = creature->GetHighestPlayerAttackerLevel();
+        if (highestLevel > player->GetLevel())
+        {
+            // Level ratio: same as group formula (playerLevel / sumOfLevels)
+            uint32 sumLevel = uint32(player->GetLevel()) + uint32(highestLevel);
+            float levelRate = float(player->GetLevel()) / float(sumLevel);
+
+            uint8 grayLevel = Acore::XP::GetGrayLevel(highestLevel);
+            if (creature->GetLevel() <= grayLevel)
+                xp = uint32(xp * levelRate / 2) + 1;
+            else
+                xp = uint32(xp * levelRate);
+        }
+    }
     if (xp)
     {
         // 4.2.2. Apply auras modifying rewarded XP (SPELL_AURA_MOD_XP_PCT).
diff --git a/src/server/game/Entities/Unit/Unit.cpp b/src/server/game/Entities/Unit/Unit.cpp
index 391bb12e3097eb..b872101a952fc7 100644
--- a/src/server/game/Entities/Unit/Unit.cpp
+++ b/src/server/game/Entities/Unit/Unit.cpp
@@ -1149,7 +1149,10 @@ uint32 Unit::DealDamage(Unit* attacker, Unit* victim, uint32 damage, CleanDamage
         {
             uint32 unDamage = health < damage ? health : damage;
             bool damagedByPlayer = unDamage && attacker && (attacker->IsPlayer() || attacker->m_movedByPlayer != nullptr);
-            victim->ToCreature()->LowerPlayerDamageReq(unDamage, damagedByPlayer);
+            uint8 attackerLevel = 0;
+            if (Player* attackerPlayer = attacker ? attacker->GetCharmerOrOwnerPlayerOrPlayerItself() : nullptr)
+                attackerLevel = attackerPlayer->GetLevel();
+            victim->ToCreature()->LowerPlayerDamageReq(unDamage, damagedByPlayer, attackerLevel);
         }
     }