Win 3 games in Team Arena - Get a score of 1000 in Warzone - Complete “Battle of Sunaion” on Heroic or harder with Iron Skull active. - Kill 10 Knights in CampaignWeekly Challenge:
Win 50 games of Arena - Beat the Campaign on Legendary Difficulty solo.
Reasons why this will help is because Halo 5’s campaign is dead. Bringing challenges will not only revive the campaign but also bring some exp and req points into the game. Obviously the amount of exp and/or REQs will correspond to the difficulty of the challenge but I think adding these challenges will bring some more variety to the game. These challenges are just ideas derived from my countless hours on Reach but its a start.