They aren't "competitive" in the sense that you'd never use these decks in standard, but that's the beauty of theme mode: you'll only be competing against other, equally powerful theme decks
Similar to how Duraludon VMAX is seeing success again, Giratina VSTAR can toss in a couple of copies of Temple of Sinnoh [Astral Radiance] to start hurting those Special Energy
A: There are 2 areas where you can enjoy some Yu-Gi-Oh
It's built to pick off benched threats while staying mobile, making it a flexible pivot piece for Electric-focused or hybrid decks
Palkia VSTAR is the direct evolution from Palkia V, making it harder to play, but the VSTAR power is strong and the secret art jumps off the card
For two prime examples of fantastic reprinted cards, look no further than two of the evoke Elementals of Modern Horizons 2 : FuryFury and EnduranceEndurance