summoning like Final Fantast

Hello, i'm looking for a way to summon a monster like Final Fantasy.
to do this is need the char art in battle to change, i cant seem to get this to work. Not only the art change but i need it to have life change to.  Well switching heros in battle is the best wat to do this but how.
or if you know anyway at all this can be done.




        Thank You.

Spent 3 hours trying before i paged.
Then 10 mins later i figer it out.
Anyway i dont know how to remove my post.
 

I"m just makeing it a Common event then adding it into  a skill.
After that only one problem stands the level of the skill. i want them{player} to find and use them{the summon mosters} at any level....  i'll most likly just add into the storly line that you have to be a exp summoner to summon them. anyway no need to replay to this.

 Thanks