Yeah, there's still the limit of one power per turn, and the Bell and Vocalize are the only ones that let you use a Rhythm, and Legacy can only Galvanize once.
Still, I did miscount the one against Plague Rat. My bad.
Whoops, my bad! I was Galvanising twice 
Polyphoric Flare will get you an extra point all right, but the problem is you need it or Alacritious Subdominant to get the damage boost from Syncopated Onslaught up to two.
I was already factoring that in. I was using the harp with supertonic and subdominant for an extra galvanize and an extra vocalize.
Actually, I came up with a little extension. All of that happens, but on Omnitron's turn he uses Time Slip to have Argent Adept play a polyphoric flare, giving him an additional +3. Thus, 206.
The problem is, the +3 combo only works twice; each requires the destruction of an Alacritous Subdominant, of which you only have two. It might be possible, if you're at the end of your deck and then reshuffle so that the Subdominant is on top, but it'd be tricky to work out, even hypothetically. Erm... I guess you could use a Flare on your turn to get the +3, then use your power phase to activate Omnitronks' power and play Vernal Sonata, and put the Subdominant on top of your deck, so you'd then draw it. Then Omnitronks on his turn Timeshifts AA, throwing out a Silver Shadow. He can use tha to give another +3, then use Silver Shadow to play the Subdominant in his hand? Does that work?
Fixed Point.
Oh, of course, I forgot about that card that's vital to make this entire combination actually. work. Silly me again.
Also, Alacritous Subdominant is not destroyed until after fulfilling the extra power use. Thus, if the extra power activates another use of Alacritous Subdominant, it is not yet destroyed and can be used again. Only once you’ve finished using that power do you destroy it, thus limiting it’s use to effectively once per initial power use rather than once per activation. Of course, Fixed Point makes this point moot.
(Every time I think of Fixed Point, I think of the Dead Sea in Chrono Cross (which is how far I’ve made it in the game before taking a hiatus.)