Ensembles and Arsenals are currently only available for the Warlords of Draenor season. Arsenals Include all weapons from that season, even ones your class can't equip. Ensembles Include a specific class armor set.
1. You will get Ensemble: Wild Combatant's Armor.
2. You need to provide your account.
3. Your character's level should be 110.
4. ETA: 3-5 days.