>>537741534
Probably not much of a surprise but that deck's too old to just modify a bit and find success with. If you really really really want to use the Assault mode stuff, then Psi-reflector is good. He adds Assault Beast then summons it from the GY after it discards itself so you can make a synchro. And Assault Sentinel also can get you to Reflector.
But I wouldn't suggest doing that since it's not very good these days and isn't enough to build a deck around.

If you want a modern deck that's similar to the psychic half then the P.U.N.K. cards have a bunch of psychics that pay LP then make synchros and are pretty good. But aesthetically they're very different.

If you're willing to wait half a year then there will be retrains for a lot of the old psychic cards that will release and you can make a deck around.