Entropy: Zero 2 (Half-Life 2 mod) Final fight with Combine advisor with friendly Vortigaunts
You can use Xen grenades to spawn friendly Vortigaunts who will help you with fight with advisor. However in my walkthrough, I decided not to use them because I wanted to defeat advisor only my myself, but I recorded this fight anyway to show you other opportunity and secret dialogues after winning this fight (if some of the Vortigaunts will survive).