Indra
Uses Zeus to shoot horizontal lightning blast (Similar to Stollen Fire).
Mamaraid
Combines Hera with Napoleon, jumps in the air, spins around to gain momentum and slams down on opponent
Fulgora
Uses Hera to shoot massive horizontal lightning blast (direct improvement on Indra).
Tenman-Tenjin
Uses Hera to create enormous lighting storm, covering large area with several strikes and electrocuting everyone within it.
3-Combined Attacks (3 Homies)
Maser Saber
Merges all 3 homies and generates enormous energy blade capable of slashing buildings in half with one hit.
Maser Cannon
Merges all 3 homies and releases enormous energy blast capable of destroying everything in direct path.
Mother’s Homing Canon: 3000 Leagues of Misery
Merges all 3 homies to create sentient lightning/fire being that attacks opponents and is capable of homing and tracking targets.
Ocean Sovereignty
Combines with Kaido to release massive shockwave capable of intense destruction to all surroundings.
Big Mom has also displayed several other devastating abilities, including Raitei (merges hand with Zeus and strikes down with huge lightning bolt) and Heavenly Fire (merges hand with Prometheus and strikes down with immense flame punch), on Whole Cake Island. She has also previously combined her Homies in a form called Cognac (enlarges Napoleon to size longer than a standard ship and coats him in Prometheus’ fire). She has not just demonstrated a mastery of her abilities, as seen on Whole Cake Island, but also somehow evolved them during her time on Onigashima.
I think it is safe to say one can easily understand why Big Mom, with her abilities, crew and territories stands as one of the most powerful pirates of her era. It’s insane to think that new pirates are rising to take her place and I think these fights in Wano showed that the individual gap is still impressive.
That being said, even more credit to Kid and Law (and everyone else) for finding ways to combine their abilities to not only match but eventually overcome the enemies in front of them.