Right now I've got a trigger_once, a monstermaker for a single headcrab, ambient_generic for the sound, but I can't make the portal itself properly because for most rendering modes it has black instead of being transparent, and for glow and additive, while it looks fine in the editor, (jack btw i dont know if it shows sprites in hammer,) it doesn't show in the game. And yeah I have the trigger linked to all of these.