、・・・。
Well then, shall I show just a hint... of my real power?
Literal
Well-then, faintly... real-power [object-を] let's-show [casual-かね].
ほんのり ('faintly, just a hint') applied to unleashing power is deliberately understated — a classic understatement trope in fiction. ですかね combines the polite question です + か + ね (seeking gentle agreement), but the speaker is really talking to themselves. んじゃ (contracted では) is a casual 'well then.' The ellipsis builds dramatic anticipation.