How would you make MJ a good Venom character?
I would make it have a more serious but fun tone.
It would all have to start with a major revelation now that the mystery box would be over.
Have Carnage figure out who Venom is
Paul gets fridged by Carnage [Eddie either won't know or is horrified he couldnt stop it]
MJ learns with Great Power comes Great Responsibility
She goes to Peter for Comfort
She ends up back with Peter, he's still freaked out by the symbiote
Lots of cheesecake covers of her
Peter and her tagteam Felicia for kicks
Let them get married again
Have her be as cool of a Venom as Flash
When we get bored of her as Venom, life foundation manages to blast Venom with sonics hard and separate her. Symbiote gets hurt so bad its mind-wiped to like Web of Spidey 1/PPSM 99 pre Venom jumps host to host no personality.
Eventually it tries to get with Peter again but is rejected...goes back to Eddie who may be mentally scarred by Carnage/escaped Carnage bond somehow. Maybe he's catatonic in Ravencroft or something. Symbiote needs to relearn everything it has and has a new chance at not being lame.