Here's my overall thoughts on Shadow Puppet.
Overall I really enjoy playing with her a lot. She ties in stats with Djinn Frizz, therefore she also has the second highest attack stat in the game. Likewise, she will be prone to sweep most teams with relative ease, with the addition of Fukua's L5 being low combo, making her viable for Futile Resistance for example.
The buff and debuff reset SA sounds somewhat overwhelming due to its 5% proc chance, but it's fairly balanced thanks to Fukua's high combo potential. For one to try and take benefit from it, it goes without saying that having moves capable of debuffing or buffing, or just carrying a support like Surgeon General or Pea Shooter is required to get the most out of it. Being able to reset buffs and debuffs is awesome, but not very feasable on rifts. She beats Claw N Order by not requiring crit rate to reset, therefore being capable on using the SA with That's All Folks around, but otherwise Claw's odds just scale up higher (without crit investment it's about 10% chance).
But by far the biggest selling point to Shadow is the time stopping SA, and it's alright. Just think of a second wind fighter like Necrobreaker or Robocopy, but can also stop time. It's mostly a fancy lifesaver, which does need very careful play, otherwise you might waste the Miasma gained. That's why I highly reccomend to run either Twice Shy or Inevitable Snuggle. Also, be careful not to make an attack on accident, since that cancels the time stopping. One last thing, if the AI killed you with a regular BB, you won't be able to use one yourself if the opponent's is still active. Most common example would be Big Band's Super Sonic Jazz: dying midway the attack will still keep it active leaving you for dead.
As a whole, Shadow does require a lot of careful play, because despite having a safety net in case of recklessness, it's not a guaranteed life extension. But if you can adjust to her respective settings, she can be a very strong fighter.