Secrets Of Mugwood is the first DLC of OrbusVR, and features a four new zones, new cosmetics, mounts and pets, and a new main questline and a few side quests
It can be bought from the in-game shop for 9.99$. Like all purchases, the DLC will be unlocked for all characters tied to that OrbusVR account (as well as newly created ones).
These weapons can be obtained by defeating monsters inside the zones of the Secrets of Mugwood DLC. The spider weapons drop from most spider enemies, while the other type drops from non-spider monsters.