Simply abuse the Chain Yanker + Yes Man Kablaam tactic, unleash godhand and punch the remainder of her life the normal way and evade whenever needed.

When attacking the normal way, keep punching until she attempts to attack. Shannon doesn't gain invincibility frames when she does her wand-dance moves (non-projectile) so you can punch her a few times before back flipping away to safety. As she's recovering, run up to her again and repeat. You can also try to get in the occassional guard breaks.