Here is the full list of items received as you level up any Class :

Reaching Level 3 (Provides the following) :
  • Minor Battle Solution x10
  • Shellback (7-Day Back Accessory) x1

Reaching Level 14 (Provides the following) :
  • Minor Battle Solution x10
  • Village Atlas (15-Day) x1
  • Bonzai (7-Day Auto-loot Pet) x1
  • Angry Little Cloud (7-Day Head Accessory) x1

Reaching Level 20 (Provides the following) :
  • Uncommon Noctenium Elixir x10
  • Happy Penguin ( 3-Day Footsteps) x1
  • Strongbox Key x1

Reaching Level 30 (Provides the following) :
  • Major Battle Solution x10
  • Fuzz Cop Car (7-Day Mount) x1
  • Strongbox Key x1

Reaching Level 35 (Provides the following) :
  • Valkyon Health Potion x10
  • Azure Butterfly Wings (7-Day Back Accessory) x1
  • Strongbox Key x1

Reaching Level 40 (Provides the following) :
  • Rare Noctenium Elixir x10
  • Retro Wizarding Hat (7-Day Head Accessory) x1
  • Strongbox Key x1

Reaching Level 45 (Provides the following) :
  • Bravery Potion x5
  • Skycycle Mk.7 (7-Day Flying Mount) x1
  • Strongbox Key x1

Reaching Level 50 (Provides the following) :
  • Goddess Blessing x5
  • Rejuvenation Potion x10
  • Winged Band (7-Day Head Accessory)
  • Strongbox Key x1

Reaching Level 55 (Provides the following) :
  • Prime Battle Solution x10
  • Sapphire x1
  • Jetcycle MHx-7 (7-Day Flying Mount) x1
  • Strongbox Key x1

Reaching Level 60 (Provides the following) :
  • Superior Noctenium Elixirs x10
  • Discoball (7-Day) x1
  • Emerald
  • Strongbox Key x2

Reaching Level 65 (Provides the following) :
  • Diamond x1
  • Metamorphic Emblem Chest x1
  • Rainbow Cloud (7-Day Head Accessory)
  • Strongbox Key x3

Reaching Level 65 - GUNNER ONLY (Provides the following) :
  • Purple Will Suit (Permanent Costume) x1
  • Celeboom (Permanent Weapon Skin) x1