Hi,
I am following a build from Alcast for solo magicka templar which calls for the following in gear setup 2.
Chest - Law of Julianos
Belt - Law of Julianos
Shoes - Law of Julianos
Pants - Law of Julianos
Hands - Law of Julianos
Head - Iceheart
Shoulder - Iceheart
Necklace - Mother's sorrow
Ring - Mother's Sorrow
Ring - Mother's sorrow
Weapon 1 - Mother's Sorrow lightning staff
Weapon 2 - Crushing Wall or Mother's sorrow
I have all the set except the iceheart helm which i'm working on getting and I have just obtained a Normal Maelstrom staff but my question is, and I apologise if this sounds like a noob question but I don't know much about the maelstrom set.
Going off that build if I was to use the Maelstrom weapon on the back bar then I would lose the 5 set bonus from Mother's sorrow, so I figured that there must be a gain from using the Maelstrom staff. The Maelstrom staff says in the tooltip that you get the benefit from the 2 items equipped

Can someone explain to me the benefit of dropping 5th set bonus from mother's sorrow to a single Maelstrom staff on backbar please?