Evolving a Pokmon doesn't heal it from any damage, but it does remove any debilitating status conditions causing it problems, which can come in handy
Y'shtola's abilities as a Commander aren't anything to laugh at either, even if they don't have as much massive combo potential as some of the other options in the set
The lore behind them carries a quote that describes them as, "The messengers of Inferno who burn everything in their path!" This, of course, is a direct reference to demons from Hell which these monsters are based on
9 Penny Helps Players Pivot Their Game Plan First Printing: Scarlet & Violet Base Set Most major meta-relevant decks are required to evolve their Pokmon to thrive because the basic Pokmon in the deck are not reliable attackers
Everything is correct in the coding so I guess it's just glitching.
Brudiclad, Telchor Engineer requires a lot of the same setup steps as Esix, Fractal Bloom