Serena's personality in the anime is nothing like her in-game counterpart, which dissapoints me. She seems more close to Shauna than Herself. For accurate ones... Honestly, most of them are very different. Maybe Cyrus?
I'm gonna be honest with you, the protagonist characters from the games literally have
no personality. I know the in-game Serena when she's your rival is basically just "the smart one" of the group. Since there's not much personality to go upon for the protag characters, stretching their personality is... all that can really be done, honestly.
Cyrus was accurate, indeed.
I'm going to go on a limb here, but, one of the characters that's really accurate is
Fantina. In her one time appearance, she was actually extremely accurate to her game depiction. Speaks French, competes in Contests, etc. I'd say Sinnoh was the region with the most accurate characterizations.
The only main character I felt was of any accuracy at all besides the Gym Leaders was this set of characters: Barry, Bianca, N, and Team Plasma, (Ghetsis included). 90% of the anime characters I suppose, are taken to their own interpretation, but these characters are the most accurate for sure.
As for characters that aren't accurate at all? Um... well, plenty.
Mostly the protagonists, since they're taken differently. Maybe it's because the anime wants to flesh them out, so they're not exact carbon copies of the way they are in the games? Maybe.
