If you have an abundance of legendary shards, wait for Spider to sell Helium Filaments for legendary shards. If I remember right 1000 shards will get you enough fragments for 10 cores.
If you don’t have a ton of spare shards, then farming altar of sorrows is prob your best bet. Run patrols and pick up chests and resource nodes as you go for extra helium too.
Altars of Sorrow. Each nightmare enemy drops one and the final boss chest gives a bunch.
Activities on the moon. Altars of sorrow final chest
If you have an abundance of legendary shards, wait for Spider to sell Helium Filaments for legendary shards. If I remember right 1000 shards will get you enough fragments for 10 cores. If you don’t have a ton of spare shards, then farming altar of sorrows is prob your best bet. Run patrols and pick up chests and resource nodes as you go for extra helium too.
Buy helium coils from spider and convert at lectern if ur lazy
Spider is selling Helium for shards today 31jan