This is simply me adding Kitty Pryde to Cozy Snap's Kill Bounce deck build and seeing how it plays out. Instead of Kitty, you can run Mysterio and whilst it plays out differently the play style is about the same.
General turn order:
Turn 1 - Kitty always plays if she's in your hand and it's possible to play her. If not then we play Iceman, Yondu, and The Hood in that order. Nova can be played turn 1 but sometimes it's best to hold on to it.
Turn 2 - Again, Kitty if available. Follow the priority order for Turn 1 here and add any 1-cost card to the board with Kitty. Try to stack one lane so that it's possible for Beast or Carnage to do their thing.
Turn 3 - If you have Hit-Monkey in hand you can play that along with Kitty in a lane. If you have Beast in hand, hold on to it for now. If you have only 1 cost card, follow the priority above but be sure to leave a spot in the lane you're filling for Beast/Carnage.
Turn 4 - Ideal position here is you have a lane with Iceman and Hit-Monkey sitting in it. If so, play Kitty and Beast plus any 1-cost card in another location. Alternatively, this is where you can start charging up your Death by destroying a location's cards with Carnage - naturally, be sure to play Kitty elsewhere. Also at this point, you can play Moon Girl if you have 2-3 favorable cards that you want to copy.
Turn 5 - I would Moon Girl and Kitty Pryde this turn, although you can leave Kitty in your hand (potentially with high power at this point) and play another 1 cost card instead. The ideal situation here is that we're charging up a big final play with our low-cost cards or we've reduced the cost of our Death. Also, an option here is to skip so that your She-Hulk is 1 cost, a great option if you copied her on Turn 4.
Turn 6 - Dump your hand! Be sure to budget for Kitty if you haven't been able to Beast her.
Moon Girl is great for if you have a great few cards to the left of your hand but you do not need to play her all the time. Similarly Kitty ideally wants to be played every turn but with Killmongers out there sometimes it's worth holding on to her for a turn if you suspect it will be played soon.