Exotic armor sets.
Armor sets that reward specific play styles and end game players that are hard to get either a long quest/bounty line. Each piece is exotic and can be used normally with other legendary armor, but can be equipped with the other exotic pieces of the set for added bonuses.
Perks activate and stack when all 4 pieces equipped(individual pieces grant +2-5% that add to a total of +15%).
Stat rolls are distributed so when all equipped you have 75% of intellect, discipline, and strength.
For hunter: Fenrir's Ferocity (lone wolf style)
Perks granted when all 4 pieces are equipped: Kills of any kind reduce grenade/melee/super cool down and a chance to produce and orb of light. Boosts to agility and recovery speed.
Individual armor perks:
Helm: Fenrir's Gaze: radar stays active always and has better vision in darker areas. Better target acquisition.
Gauntlets: Fenrir's Claws: increased melee speed and recharge, grants back stab at all times and causes bleeding damage.
Chest: Fenrir's Mantle: spawn more orbs, chance to survive a fatal shot with a burst of health recovery.
Boots: Fenrir's Speed: increased agility(similar to MIDA) and an additional jump.
Edit: I am working on the equivalent armor sets for both titan and warlock. It takes a while to type and think of everything. I also plan on doing concept art for all three.