I spammed it non stop, and killed emerald weapon.Anyone else find it cheap?

Its funny too, cause it is getting wailed on mercilessly, and until the spell is over, it can't do anything, and if you time it perfectly, you might avoid it being able to get a turn sometimes.

Link it with W-Summon... then see the show...

I still think W-Summon + Quadra Magic + Bahamut Zero and with Mimic Mastered Materia on two others is just as overkill...

It's only cheap if you use the Underwater Materia to remove the 20 minute time limit you would have otherwise. Besides, timing is equally important as the setup - one second too slow would give the beast breathing space to unleash something like Ae Ir Et Am Storm.