i think for the lines that seem a bit confusing, tats is claiming that to be an esper, it's common to be mentally prepared against leeches/being solely independent as you know people will only hang around you for these powers (which is why throughout the series she's always constantly emphasizing independency to her sister as well as for herself). and since op villainness basically admitted she got her powers from someone else, tats understands she's not mentally prepared to handle being such a powerful esper, and that's why she's vulnerable towards the "strage" (i want to say 'strategy') of others using espers, and therefore the fact that she depended on others for power is basically them just using her as a pawn/experiment.