Thankfully Otto is a flying type so half of the Nidoking's main form of attacking doesn't work. Otto uses Air Slash but it is deflected with ease. It hits her with a Thrash knocking her down. She gets back up but due to the Nidoking's ability, she's poisoned.
Giovanni: Now that you've been put on a timer, let me ask you a question. What is your purpose in all of this. Do you really think some kid is going to get rid of the biggest crime syndicate?
Otto: You guys hurt my friends, that all. Getting rid of you will make them happy so it will make me happy.
Giovanni: Sad, do you even have any ambition of your own?
Otto: I'm the only one of us that didn't have dreams of winning the Pokémon League but they helped me and my family so I'll help them. That's all I have to say to someone like you.
She use Roost to quickly recover some of her health before the Nidoking hits her with an Earthquake. She sends more Air Slashes at it and it again deflects it. She uses Wing Attack with both her arms and wings and slices through Nidoking. Giovanni takes the opportunity the have Nidoking use Megahorn to pierce through Otto's stomach. Now severely injured she tries to use Roost but that just gives Nidoking the opportunity to use Earthquake.
Giovanni: See what you've done yourself? We only did this to get rid of Sabrina and turn Silph Co. into our new headquarters after we lost the game corner. You and your friends were never even supposed to get involved. But look at you now, a hole in your stomach and dying alone. This is all your fault.
Otto: I don't care. Rai and Wart fought so hard to defeat your clone in Celadon City. If they were able to, then I can. I'll put the rest of my life into this technique. Air Slash: Wing Blade!
She coats her wings with Air Slash and goes in to attack Nidoking. She's smacked down by its Thrash but still hits her attack, a critical hit.
Giovanni: Hmph...
He returns Nidoking to its Pokéball and behinds to walk away. Sabrina gets back up to stop him and blast him against the wall. Again, this Giovanni is another Ditto in disguise.
Sabrina: Sorry Otto. Putting a child like you through this is unacceptable. Alakazam, take her to the Pokémon Center, let's hope they can help her.
Episode End.