How to increase the eternal level of this assassin disc, and what items are needed?

[komarchucky]

[Golem]

Welcome to DQ Forums @komarchucky

raising the level of an Eternal Item is one of the many things you can’t do with Crystals.

here is a post on the subject:

Bad luck? Crystal affix weaker than epic affix

for the HP & MP on hit, Crystal only doubles instead of triple, so same value as Epic on Eternal Item. from +250 to +500 instead of +750. I think there is a game balancing reason for this. Edit: also, Obsidian can be used to improve your Crystal Affix now, not just Diamond. and only a few Crystals can be used on Eternal Items.

hope this helps.