How is Valls seen in Spain? His public image in France was not amazing when he left (he was a socialist but left the party to join macron, and now you're saying he joined the right wing? )
well, spain... keep in mind he's only involved in the politics of barcelona, which is the capital of catalonia, which is only a part of spain. and he didn't even get that many votes, despite pairing with a well-established party as "ciudadanos". which have already broken the deal with him anyway.
in general, I'd say the consensus is that he's an opportunist. he knows how to play politics, but he's an opportunist. we are aware of his image in france.
in my opinion, he only joined ciudadanos for convenience, so he could enter the game in a decent position, and now he will attempt a transition towards the socialist party (if they want him, and it's still way too early for this, we probably need to wait 4 years until he's free of his current responsibility in barcelona). this is highly speculative on my part, but it's the way I see it. enter the scene through ciudadanos, and then distance himself through his actions, not leaving ciudadanos himself, but rather being rejected by the party itself. first by criticising the idea of ciudadanos being part of an agreement in madrid to have the support of an extreme-right party (Vox) so the right-wing parties could have the city council, and later, just a few days ago, by giving Ada Colau the support to be named mayor in barcelona, in exchange for "nothing". he's good at navigating the waters, he has experience at that, but everyone knows he's just an opportunist. he's already in the middle of the first scandals regarding some businessmen paying him 20.000€ each month for his involvement in politics. anyway, there are bigger things at play in catalonia with the independence process and all that, so in general people doesn't even care much about him. he's lucky to have that.
For a few months he was a "hero" of sorts for the spanish right wing, since he was viscerally unionist (i.e., against catalan sovereignty), and this is a basic tenet of spanish right wing. Now that he has supported the current mayor of Barcelona to be re-elected, he has fallen out of favor (since the mayor is left wing and somewhat neutral on the independence question).
For left wingers and non-unionists, he's always been nuts.
