While it's still unknown what exactly made Satine and Bo-Katan Kryze to turn on each other but as of this episode, Bo-Katan finally comes to understand what her sister was trying to do. What good did her people's warrior culture ever do? They had brought nothing but internal fighting within the Mandalorian race and this lead outside forces to take advantage of the situation which becomes truer than ever when Maul took over the planet. Bo-Katan now had a My God, What Have I Done? moment and this lead her to her initial refusal to take the Darksaber for a while.
It gets worse- historically, in both legends and canon, the idea of a Mandalorian society being taken over by a Dark-Side user and made to serve their ends? This tends to happen a lot in their history. In Legends, the events of KOTOR were prefaced by the Emperor of the Sith pointing the Mandalorians at the Republic and Jedi and saying "Go," which led to the rise of Revan. This is just the latest (and most direct) example of Mandalore's warrior nature being manipulated.
Gar Saxon also had the same epiphany as Bo-Katan did. His decision to stand by the Mandalorian ways resulted in him following a leader who had little qualms sacrificing soldier after soldier to get what he wants. It makes his decision to attack Sabine after she bested him into a different light: after being handed the short end of the stick by Maul for following traditional Mandalorian beliefs, he's decided he'd rather be killed on the spot than be imprisoned again.
While no Mandalorian physically fought Maul outside of Bo-Katan, Ahsoka's mo-cap actress is also the same stunt actress for the Mandalorian Armorer, so in a certain point of view, a Mandalorian IS fighting Maul to protect Mandalore.
Ahsoka claims that Maul hadn't though his plan too well, given his plan was to kill Anakin but if he had trouble with her then he was doomed against him... But it didn't really matter as long as Anakin showed up, as upon being apprehended Maul could simply tell him that Palpatine is his master, or claim he's under his influence and at the very least damage Anakin's trust in the Chancellor.
Maul's behavior in this episode goes way beyond simply knowing what Sidious is about to do. It is highly likely he's seen visions of the upcoming violence, explaining why he's so unhinged.
Palpatine probably also tortured him quite a lot, partly For the Evulz and partly to turn him into a more reliable puppet on Mandalore
