Brazilian lawyer here:

Judge Moro was quite literally ruled biased by the Supreme Court as he and the prosecutor would literally text each other with ideas on how to best proceed to condem Lula, and Moro would give the prosecutor tips on what to file. If Lula was so corrupt and if there were so much proof against him, why would it be necessary for the judge and the prosecutor to do that?

The Court of Appeals and the Superior Court of Justice both used the cases and evidence gathered in the first degree to base their rulings, sonit really doesn't count.

Lula did indeed apoint many judges to the Supreme Court, but unlike Bolsonaro and Temer, Lula (and Dilma) always selected a candidated from a list of three that was compiled by other jurists, exactly so that whoever reaches the seat doesn't owe anything to the president and can be unbiased towards them. The whole reason that Car Wash wasn't archived the moment that it reached the Attorney General's desk is precisely because, just like Supreme Court justices, the Attorney General was always picked from such a list (that stopped with Temer and Bolsonaro, who picked people that would have their backs).

As for most corrupt: have you seen Bolsonaro's card expenses? Have you seen all of the corrupt practices that he was involved in? The guy literally delayed the purchase of COVID vaccines because he wanted to get a few dollars for each one. Hell, his whole family is involved in hundreds of corruption scandals, just a few weeks ago we learned that the former first lady had the fish from the Planalto Palace killed so that she could collect the coins that were thrown in its pond.

But even so, I'd rather have a corrupt in office than a genocidaire (especially a corrupt genocidaire)