Brona.

So I'm crap at drawing humanoids so just try to visualize this with me.

Sona, disguised as a frat boy, ala teen comedy style. Cargo shorts, a generic sports shirt that's overly baggy to hide her chest, university hat or keep with the beer hat theme that Brolaf has, etc. Everything she says is in this deep goofy voice put on by her current voice actor. Her phrases will be said without much confidence since she's trying to pass herself off as a frat boy here, such as:

"Heh, heh, yeah! I love the sports!"

"Are we uh, going to get some brewskies?"

Etc.

Instead of her harp, she has a portable beer pong table strapped to her shoulders, stocked with cups.

She whips ping pong balls at her enemies/allies instead of musical bolts.

For her ultimate, she flips her table, dousing the enemies in beer and stunning them.