(stops to consider a moment...)
Ok, so two sprites can merge. Are there rules to this?
EG, think for a moment:
You have a null, sterile session, kinda-sorta:
Instead of no sprites prototyped, and thus a sterile session, both sets of intro players start "Simultaneously", and prototype both of their unprototyped sprites with each other.
Eg, if we had the 4 kids-- Let's say that Jade and Rose are both in the same room together, and both start server copies. Strider and John are both together in the same house, and both start client copies.
This means that in the same house, there would be 2 cruxtruders, and thus 2 unprototyped sprites.
The unprototyped sprites are then prototyped together. This essentially destroys a sprite, but advances the game field 2 stages, because technically BOTH sprites were prototyped. (No new powers or features are given to the prototyped sprites.)
If the other two players do the exact same thing, that destroys another sprite, and advances the board another 2 steps.
Once all 4 players are in the incinisphere, the two remaining sprites are prototyped together, advancing the board to the final stage, and destroying another sprite.
By doing this, the resulting bad guy has a null power set. The kids' normal powerups would more than make it possible to defeat him.