Fix _DespawnAtEvade for other creatures to actually respawn said other creatures.

Also fix add aggro for Hadronox.
Fixes and closes #18012.

src/server/game/AI/ScriptedAI/ScriptedCreature.cpp

@@ -569,7 +569,7 @@ void BossAI::_DespawnAtEvade(uint32 delayToRespawn, Creature* who)
         return;
     }
 
-    me->DespawnOrUnsummon(0, Seconds(delayToRespawn));
+    who->DespawnOrUnsummon(0, Seconds(delayToRespawn));
 
     if (instance && who == me)
         instance->SetBossState(_bossId, FAIL);

src/server/scripts/Northrend/AzjolNerub/AzjolNerub/boss_hadronox.cpp

@@ -789,7 +789,7 @@ struct npc_hadronox_foeAI : public ScriptedAI
                                 me->GetMotionMaster()->MovePoint(MOVE_HADRONOX, hadronoxStep[2]);
                                 break;
                             }
-                        me->GetMotionMaster()->MoveChase(hadronox);
+                        AttackStart(hadronox);
                     }
                     break;
                 }