A bad sound guy can always destroy your sound. No box can avoid that.
If this happens again, explain to the audience that there is a technical problem so you are unable to play and that it cannot wait until the next set break to correct it.
Stop playing, go to the soundguy, correct the EQ yourself or tell him what to do and tell him that he is not allowed to touch your EQ or next time you stop playing for the rest of the day/night and explain to the audience what kind of technical problem there is (the soundguy being unable to do his job).
A preamp with a good EQ, HPF and DI out can give you a bit more control over your sound after you told the sound guy not to touch your EQ, but if he still turns your knobs no box will help.
The redeye might help to reduce mud in the output signal, but the soundguy can always turn up the bass frequencies to get the mud again. With EQ before the DI out you can correct it for a short time that might bring you over the rest of the set.
Talk to the person that pays you and him to give some money from his to you as you need to get more equipment to be able to correct a misbehaving sound guy. That might help the next time.
I once had this with a large untypical tango orchestra. The leader wanted me to be amplified (not really needed), the sound guy turned the bass frequencies up so there was a lot of mud.
I first tried to compensate by turning the output volume down but the guy turned me up at the board again, then I corrected the EQ at the board in the set break when the sound guy was away, but after being once more "corrected" by the sound guy I finally turned down the output signal to silence.
I think the sound guy freaked out a bit after that, but he was very far away in the dark.