I messed around a bit with what you told me. It seems like it's unnecessary to add more options to the EnchantItemOptions.xml. I can just straight add them to the item stat xml with the "on_enchant" parameter.
Here is the the Damaged Antharas Earring stats:
<item id="90993" name="Damaged Antharas' Earring" type="Armor">
<!-- Severly Damaged Antharas' Earring. With the help of Balthus Knights' Varnish, Balthus Knights' Matte Varnish, Balthus Knights' Shining Varnish it can be enchanted up to +10. Starting from +4 adds passive skills. Damaged Antharas' Earring +10 can be exchanged for Antharas' Earring. -->
<set name="icon" val="icon.accessory_earring_of_antaras_i00" />
<set name="default_action" val="EQUIP" />
<set name="bodypart" val="rear;lear" />
<set name="immediate_effect" val="true" />
<set name="material" val="WOOD" />
<set name="weight" val="10" />
<set name="is_sellable" val="false" />
<set name="enchant_enabled" val="10" />
<skills>
<skill id="3558" level="1" type="ON_ENCHANT" type_value="0" />
<skill id="3558" level="2" type="ON_ENCHANT" type_value="1" />
<skill id="3558" level="3" type="ON_ENCHANT" type_value="2" />
<skill id="3558" level="4" type="ON_ENCHANT" type_value="3" />
<skill id="3558" level="5" type="ON_ENCHANT" type_value="4" />
<skill id="3558" level="6" type="ON_ENCHANT" type_value="5" />
<skill id="3558" level="7" type="ON_ENCHANT" type_value="6" />
<skill id="3558" level="8" type="ON_ENCHANT" type_value="7" />
<skill id="3558" level="9" type="ON_ENCHANT" type_value="8" />
<skill id="3558" level="10" type="ON_ENCHANT" type_value="9" />
<skill id="3558" level="11" type="ON_ENCHANT" type_value="10" />
</skills>
<stats>
<stat type="mDef">50</stat>
</stats>
</item>
Thank you for the help, I will finish with the rest of the damaged epics.