2 items: Adds 25-1096 Maximum Magicka
3 items: Adds 3-129 Spell Damage
4 items: Adds 28-1206 Maximum Health
5 items: Your fully-charged Heavy Attacks deal an additional 8% of their Max Health as Oblivion Damage. This can deal a maximum of 186-8000 Oblivion Damage.
The set consists of light armor and jewelry in all slots, as well as weapons and shields of all types.