About seals

Well, you are wondering how Danzo can control Minato with a seal. The seals Danzo used were not made by him; instead, he combined various seals from the Uzumaki village, which was destroyed due to Danzo's spies revealing patrolling timings and leaking information to other villages. After the clan was destroyed, Danzo took S-level sealing techniques and combined them to create a few more, like the tongue seal for Root members. The seal he used during his fight with Sasuke is one such example