Master Assassins and Mediterranean defense

[Canhoto]

I have a question for something I never really tried and I got curious about it on my current playthrough.

I have all Constantinople dens locked, which means I have all my Master Assassins.

My question is can I assign Master Assassins to a den in Mediterranean Defense and if so, what happens to the Constantinople den that Master was assigned to? Is he still that den's Master or do I have do level up another recruit to that level? How does that work? Another den master mission?

TIA

[BloodyMares]

Once you assign a Master Assassin, I don't think you can send them away. They're locked in with that Den. However I played a long time ago. If you can, then nothing happens. They still protect your den, even if they're not physically present there. You can't level up more than 6 Master Assassins, as they are part of the story. You can't get them killed either. They're forever with you.

[tony92]

You can send away master assassins. Their dens stay locked.

[reg1s7]

You can assign Master Assassins to Mediterranian and call them back anytime. The den will stay protected as far as I know.