Hey Da Fist!
I just read your story concept and it's an improvement but I think we should make it more with comedy in mind. Maybe tone it down in scale.
For example,
Two Wizard Apprentices have hated each other ever since they were born and are told by a shady, mysterious guy about an artifact that will make one of them a master wizard in an instant. The kids reach the artifact at the same time and decide to fight each other trough their summons (the players). Due to their inexperience, their champions are deformed and sometimes incomplete. In the end, they find out the artifact was a lie (pun intended).
or
The kids reach the artifact but too late they find out it is a lie. It's use casts a curse on them, empowering both yet transporting them into an isolated, ethereal dimension. They blame each other and fight it out right there.
or
The kids reach the artifact; they find out it is a simple wooden stick and are jumped by the shady guy. This shady guy turns out to be a mage himself and tricked them to steal their magic powers, something he's been doing for some time. The Kids set aside their differences and fight side-by-side against the 'Guy'.
My idea is to have 'funny' as the central driving force for the story. 'Parody', it's right hand. The easiest way to make fun of something is tonin it's importance down. Think of the Cartoon y versions of famous people. What do you think?