Challenge Mode Rewards

Elemental Crescent
Crystal-Shot Longrifle
Soul Eater
Equus
Flamegrinder
Tesseract Timepiece
Cloudsong Glaive
Face of the Guardian
Arcana Shard Spire
Staff of Infinite Knowledge
Shifting Felblade
Greatsword of the Inferno
Bloodmaw Gargoyle
Living Longbow
Sunblade
Dimension-Ripper Staff
Claws of Creation
Furnace of the Great Machine
Challengers War Yeti

Proving Grounds Rewards

Proving Grounds: Endless Damage
Proving Grounds: Endless Healer
Proving Grounds: Endless Tank