Good, now bare with me, this is the first time I am teaching something outside of my scope so I'll try and be as informative as I can. Nonetheless, as you said, Magnetism is an odd one. It doesn't directly affect the opponent, but rather indirectly, by magnetizing bodies, and then using weapons to be drawn to it. So in a sense, assume everything is first neutral. Once magnetized, it gains a certain polarity, to which said objects which you later release will be attracted. Allows for some smart customs, really. I fought one Magnetism user before, I think it was Yusei, and it was pretty cool. Very different style of approach and overall fighting, gives more depth to strategic thinking and also simply thinking ahead and placing things in the right places for later use.
Now, the techniques aren't many, so we can go through them one by one. I want you to analyze them for me, as in give me some strengths and weaknesses of the technique as well as elaborate a bit on its usages and also perform it. I know its a lot, but there are like 4 techniques, so xD. Anyway, if you're good with this, we can continue o-o.