What could go wrong?
Glockens thought that using a perfectly mundane singing voice synthesizer software, to have vocals complementing his music (since he sucked at singing even more than at playing instruments), could enhance his musical spells without any of the usual backfiring of adding more magical instruments to the basic.

Well, guess what? Magic music also mixes with regular Vocalo- I mean, singing voice software. Mixes really hard, digitalizing and mixing his human body with the software's very original  idol character (don't steal) representation of its voice.
Now she's Synth, a synthwave holographic (but able to solidify) presence with the power of magic in her voice.
The bad part is... she's lost a great part of her humanity and with a robotic behavior she awaits for commands to fulfil.