Changing up the couple for the ask game- 2 and 3 twi/champ
Is their relationship toxic or unhealthy in any way?
In the beginning, when Champion is still dealing with the whole "do you love me or the idea of Wild," there is some arguing and quietly hurt feelings. And really, yes, in some way Twilight is looking at Champion and seeing or thinking of or maybe even wishing for Wild. But Twilight's intentions are honest, and that honesty will win out over time.
In what ways are they good and bad for each other?
Twilight is going to be very good to help Champion stay present and keep giving his best every single day. He's also going to help introduce Champion to new experiences and stand beside him during his recovery. There will be some slip-ups, though, where Twilight introduces Champion to something that Wild used to love--all with good intentions, mind you--and feel Some Kinda Way when Champion responds differently from what he expects.
For a while, Champion's presence makes it very difficult for Twilight to grieve the loss of Wild. It stalls that process for him, and means that it won't be until years down the line that Twilight finally, painfully lets go of Wild's memory and accepts that this is what life looks like now if he chooses to continue moving forward.