Omnimorph

Omnimorph is a species of ancient shapeshifters with a terrifying legend. They would often kill to replace a person they shapeshifted into to lure more people into it's feeding ground. the only thing they don't eat is the skin. You noticed behavioral issues from your sister. You later find out that an omnimorph has been pretending to be her for two years. Knowing there was no other way to lure you to the Omnimorph lair, they try to convince you your sister was still alive. will you find your sister? if you do, is she dead or alive?