(This guide is based on Global, things may have been changed due to this being a private server!)
Helion armor and weapons are obtainable by the crafting system:
To enable Crafting you must visit Dora in Ardeca and select either Armor Mastery or Weapon Mastery. Once you selected either one, you need to level up your Crafting level to get to the desired level(3) to be able to craft Helion Armor/Weaponry.
How to obtain Helion Armor materials?
Undo 190+ Party Dungeon in Space Of Pilgrimage is the place for getting these items. The last boss drops either 1 of these materials:
White Knight Leader
(These items are untradeable)
You also need 10x Helion tokens: Ordeals, Blessings and Courages. These 3 items are tradeable but do drop inside the Undo Dungeon more frequently.
Once you have the following items: 10x Ordeal, 10x Blessing, 10x Courage, 1x Sun Essence, 1x Monochrome Ore, 1x White Knight Leader and a helpyron +0 armor piece you can craft one Helion armor piece!
Helion weapons are basically the same, however Helion weapons are much more of a PVE weapon rather than a PVP weapon, with the exception of Segu. Segu's benefit more from high base attack rather than the PVP dmg it gets from a Zuto weapon.