As promised, here's an example entry to my Source Rap Contest. I won't be counting this is a legitimate entry, since this battle is only to guide people on what their entry should like. 
Also, you have to include the zap sound effect Source uses in his battles(which can be found here: http://picosong.com/wn9QP/)

Lyrics: 

Goten:
Howdy there! It’s Goten, hope you don’t mind I drop in
I’ve been asked to use my Full rap Power against this chubby has-been
My big bro taught me well, I’m the cutest kid anime’s ever had
Here’s a fact: the world’s strongest also happens to be my Dad
I could throw a pile of rocks and mountains would be destroyed
I’m a warrior, a smart one too, same can't be said for you, boy
I may look cute and harmless but I’m the toughest of the Son bunch
Now I’m feeling kinda hungry, Steven shall be my lyrical lunch

Steven:
Alright what do we have here, who’s this tyke supposed to be?
He’s dissing me? I think it’s time I give you some history
The leader of the crystal gems, my show’s never been left to linger
Those bars were tickly, I didn’t know you had Cat Fingers
Goten? Well I’ll give you Ten seconds to Go
I spit rhymes in quick succession with a Lapis-like flow
Your daddy has no time to give you love, while mine actually cares for me
Peridot could call you a clod and you’d be crying to your whole family

Goten:
I can tell you’re no pushover, but you need to check your facts
Say I’ll be crying, when your show only develops through that?
Super Kamekameha to the face, you aren’t going to survive this
Now I think it’s time I diss out your group of feminists
Amethyst’s a bitch, Pearl’s too overprotective
Garnet’s a certified emo and Peridot is uneffective
And if they fused together to slay me, Dad and Gohan in song
The verse they’d make would be a true Steven Bomb

Steven Universe:
You’re a high pitched attention-seeking annoyance, and that’s that
You wanna be rude to me? I think you and Lars should have a chat
With Future Vision I can see the outcome is me winning this Gem War
Trap you in a Magic Mirror, then slice you with Connie’s sword
You wanna beat me in song? My greatest talent is singing
Take advice from your mom and just stick to studying
Trunks ain’t here to save you from this, I’ve left you beat with this verse
Now surrender yourself and get the fuck outta my universe.

Cast:
King Mewtwo as Steven Universe
King Mewtwo as Goten

Beat by Kustom
Cover Art by King Mewtwo
Written and Audio Mixed by King Mewtwo

Steven Universe vs Goten (Source Rap Contest Example Entry)

I rap I suppose. I also make rap battles and other stuff.

Steven Universe vs Goten (Source Rap Contest Example Entry)

TheMonarchy