Wow, he'd be insulted if...! No, he doesn't care at all about his apparent 'light' weight, this is some magic stuff, and Tidus is happy to be more resigned to their current state of dealing with the rat issue.

So, he calls up the spell, his clenched fist -- fortunately, not the one currently hanging around Natsuno's shoulder -- helping for that brief second of concentration before he throws it out, and a bolt comes crashing down into the water with a sizzling light.

And he can do that again...and again....to the sounds of tiny squeaks being fried each time.

What a job.