:cool: Well... you'd just use some of them like the Shields or the Sentry Gun. You'd 'summon' (ie 'drop') the monster. *poof* big guy appears, using the Shadowtrooper cloacking effect fror the right kind of 'apperance'.
http://members.rogers.com/dragonremix/image/gun.jpg)
http://members.rogers.com/dragonremix/image/gun2.jpg)
He'd be static (stuck to the ground) then hits one of your enemies with an attack, let's say a blast like from the disruptor, then *poof* he fades away. .
It would also help to add a bit of variety, have one kind stomp around for a set limit then dissapear... another could be 'lauched' from you (like Odin charging) then fades away after hitting someone. Don't forget.. not all are offensive either. You can have Toonces (or whatever the little frog guy was called) and have him cast the equivelat of the Ysalamiri protection as magic shield.
As for the story, I'd reccomend writing something Original, either a brand new FF or something that merges the 'worlds'.
As for Game types, remember you've got 3: SP, MP and 'Saga' (the MP Co-op). The last one need some REAL work to get it playable though.