With the Parasite Tadpole inside their brains, the captive Angels and Archons were no different than puppets under Dante's control, with everything that they see and hear being transmitted to him.
Previously he could only use Telekinesis to read their minds and erase some memories due to him being only a Rank 1 Animus and his proficiency in that discipline not being high enough.
But now by using the Parasite Tadpole as an intermediary, he could alter their memories and even implant totally new fake ones, and if he wanted, he could take control over their body and energy. If their souls were stronger, they could have resisted and tried to fight back, but with their current power, there was nothing they could do.
Dante did not waste time and once the Parasite Tadpole had taken control over their brains, he started to manipulate their memories, erasing everything that happened from the moment they were attacked by the forces under his command.