As Archie said, Sharpedo does shift to tank most of the damage. Super effective, but it doesn't faint the shark Pokémon. It's sturdy. All Sharpedo suffers is some HP loss and a little bit of confusion as it rolls around in the water to shake the attack off. Archie himself can't help yelping in pain from the Thunderbolt. So that's what that feels like.

"Yo, Electric Boogaloo?" he calls out, moments before Harry emerges. "Oh. There you aaaaaAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAWHATTHEFUCK"