For a certain amount of time, the homunculus shines the light of regeneration on the host.
If the summoner dies, the homunculus will sacrifice itself to revive the host. When the skill activates, intimacy drops.
If you have other items or skills that revive you on death, those items will take priority.
Higher skill levels increase the amount of HP you are revived with.

Homunculus spells light of regeneration effect to the caster, sacrificing itself to resurrect the master automatically during the duration.
When using other resurrection items, the item effect will be activated before this effect.
Resurrection recovering HP increases based on skill level.