What is the purpose of the Acquire Knowledge *on?

It begins a short battle but nothing happens when the battle is over; nothing is gained, there are no notifications or anything. There is no info for the event and nothing in the News announcement explains it either. The 'give snake skins' *on has an explanation when hovered over but the 'acquire knowledge' *on doesn't say anything.

I thought maybe since it is a 2-week event whatever function it had would be explained in the second week but it hasn't been. I also thought maybe we used the snake skins we've collected to access it since the amount given is listed directly above the *on, but it doesn't use them. Tried using with the new Orochimaru once unlocking to see if that was necessary like the arena special training but no.

So what is it for?