Why does a wizard with mana left and multiple towns get defeated instead of banished?

[Question]

As titled? I can see with the tweaker that Merlin has 78 mana left, and according to the wiki they only get defeated if they have exactly 0 mana or no other towns left. Neither is true, but after i take over his fortress, he gets defeated, not banished?

Edit : The only global enchantments active are just cause as well and its still my turn so none of the other wizards can cast spell blast. I even tried giving him 1000+ mana and making sure he had enough gold to transmute to 1000 mana, but he still gets defeated.

[Seravy]

Wizards don't try casting the spell of return if any of the following is true :
-exactly 0 mana remaining
-less than 40 casting skill
-no other towns

[Question]

Thanks, the wiki doesnt mention the 40 casting skill bit....

[Tiltowait]

Ahhh...always my favorite maneuver. I love knocking out a wizard and neutralizing his remaining towns. It's so tedious to take over a whole continent of cities...and then garrison them, and manage them, and move the workers about, and every turn be greeted with completed structures that need to be changed. It's just a real cognitive load that's not really any fun. But run a wizard down to 0 mana and defeat him...lovely. The neutral cities can be left to themselves or taken over as needed.

[Question]

Unfortunately its almost impossible for the AI to run out of mana to do that....

[Tiltowait]

It happens. You can also attack them several times per round to make them cast, or use strategic combat to make them waste mana. Maybe if you only play on Impossible.

[Anthony]

Unfortunately its almost impossible for the AI to run out of mana to do that....

Not really. It happens fairly easily early game, and even late game you can drain their mana because the AI is stupid -- just launch a whole bunch of weak attacks on AI cities that are a long way from the AIs fortress.

You usually don't want to, though, as you get 5 fame, half the AIs resources, and up to 2 spells every time you defeat an AI wizard. Defeat the wizard once, start blowing up his stacks, and when he returns kill him again, he won't have the garrison to stop you. Repeat until he's out of mana and gets defeated permanently.

[Question]

I find the AI has no problem spamming max damage spells all the time regardless of distance due to the 2x gold/mana bonus they get on normal in insecticide 1.40n...it is incredibly easy to get effectively infinite mana once you build the buildings you want as there is nothing else to spend gold on.