Just a little something I wanna work on in the future.
So we got the original in the middle, now we got Birds of a Feather Sero (bottom left), dragon Sero (bottom right), corrupted Sero (top left), demon Sero (top right), and villain Sero (top).
Here's a brighter image of the drawing
And here's the line art :] There shall be more Sero's in the making!