Code
void esv::GameMasterManager::Possess(esv::Character* character, net::UserID userId)
{
	LS_ASSERT(!character->IsFlag(CHAR_MULTIPLAYER), "We should not possess multiplayer character!");
	if (!character->IsFlag(CHAR_MULTIPLAYER))
	{
		esv::CharacterFactory::GetInstance()->PossessCharacter(character, userId);
		net::NetID netID = character->GetNetworkId();
		m_PossessedCharacters.AddUnique(netID);
	}
}


Player possession is blocked by checking the custom CHAR_MULTIPLAYER flag. You could add a script that removes that flag.

CTRL+K the elf