The second option they have to defeat all the telepaths will conserve their spiritual energy and be completely safe. But it will be slow.
However, if one of Legion isn't enough for the first option or they want to speed up the time it will take them to defeat their enemies through the second option, they could have their clones come to assist them in battle.
Just two more clones would be enough to help them overcome all of these people. And if that still isn't enough, they can always get more clones to help them out.
Legion-10 was thinking about all of these things as they got closer and closer to the Mind Palace. In just a few moments, they would get close to the Mind Palace and take it away right from under the nose of all of these people.
Apparently, they hadn't left the Mindscape. It had appeared so because they had used the Invisibility Shield divine ability. Instead of leaving or fighting, they chose to secretly take away the Mind Palace.