I have the 100 Pokemon required for the Zigzagoon and I would like it to have an Adamant nature, however how exactly do I soft reset for the Adamant nature?
Unfortunately, you are going to have trouble with this one. The nature is determined at the time the Zigzagoon is generated. You need to receive the egg without saving and then hatch it. If it is Adamant... cool. If not, you need to reset, then redo the Pokebox. It is a hassle.