Otogi 2: Tsuna's Second Weapon

[Raiden]

I've been playing Otogi 2 for quite a while now, and I must say, I can't seem to find a certain weapon. It's Tsuna's second weapon "Thunder". I've played around, and can't seem to find it.

I've looked on sites, but all they say is 'complete stage as Tsuna'. What stage?

[Kima Azure]

It's on the stage where you fight the giant spider-demon king. The one where he's berserk and pursuiting you.

Beat him (took me a while, but I did it) and you get the Thunder.