>>38568185Victini literally generates infinite energy that it can share with others. So rather than being more powerful than the Creation Trio combined, it can make all of them ludicrously more powerful, in addition to anyone or thing else it shares power with.
Also, there's time traveling Yoda to contest with, that throws out all planning the Combine could make, unless they have time travel somehow. Even then, there are many many Celebi from many times and possibly additional universes. The Combine would have to prepare for multiple realities, causalities and potentialities.
