Armor of the Seducer (AKA "Seducer") is a crafted set and is available in all armor types. The 5-piece set bonus reduces the cost of your Magicka Abilities by 8%.
This can be combined with other cost reduction stats to reduce the cost of spells even further. The other stats of the set also provide you with a lot of Magicka Recovery.
Seducer is very commonly used in PvP because it makes sustaining so much easier, which can be a challenge sometimes, especially in the No Champion Points Campaigns and Battlegrounds. The Seducer set is also commonly used by newer players that have sustain issues, because it is easy to craft and it does not take long to research 3 traits. If you need a heavy armor set (or a heavy armor piece) that helps you with magicka management, Seducer is perfect for you. It is also very popular as a leveling set.
The Armor of the Seducer set is part of the base game. Crafting stations are located in Grahtwood (Temple of the Eight), Stormhaven (Fisherman's Island) and Deshaan (Berezan's Mine). You can craft any armor, weapon or jewelry of this set in any motif style you know, as long as you have 3 traits researched (per item). You can trade crafted pieces to other players. Each set item becomes bound on equip.