There needs to be a quick explanation. The sleeper symbiote was a symbiote that Venom gave birth to which helped Eddie Brock get Venom back from his first host: a kree that wanted to destroy the Skrulls. The Light foundation symbiotes are symbiotes forcefully birthed from Venom. They were used as members of a Carnage hunting team for the Government. The hosts were killed by Carnage and the symbiotes went on to bond with a family of four but were corrupted by Carnage wielding the power of the dark god creator of the symbiotes known as Knull. Eddie's son Dylan (Who believes Eddie is his brother) Normie Osborn (The son of Harry Osborn) and the Maker (The alternate version of Reed Richards) are all working on a machine to extract the remains of symbiotes ,known as codices, from former hosts to prevent Carnage from using them to bring back Knull.
The Maker wants to test the machine on one of them to make sure that it works but Dylan obviously says no. Eddie and Peter are currently risking their lives to obtain Norman Osborn so they can test the machine on him after he bonded with Carnage and became the red goblin for a short time. But that's when some not so friendly faces come knocking. The Light Foundation symbiotes and they've come for Normie
Dylan and Normie get weapons so the can pitch in but the symbiote known as Lasher gets her hands on the Maker. The Maker just happens to have a sonic rifle on site which he uses to blast Lasher off of him.
The Lasher symbiote is blown off the host which is the daughter of the family of four. The Maker is a very cold hearted person and attempts to finish the job to which the little girl is saved by her family who still view her as their daughter/sister. Meanwhile Dylan has geared up to protect Normie.
Unfortunately, the Phage symbiote breaks through the door. It slices Dylan's rifle to pieces and drops a pretty big bomb on Dylan. Eddie is his father.
But there's not much more exposition for Phage as some very camouflaged hands creep up behind him. The snap his neck and it's revealed who it is. The son of the Venom Symbiote. Sleeper.