I'm going to give my nephews unusual gifts for their birthdays.
What sort of unusual gifts do you want to give them?
I was thinking of giving them all some sort of weapon, also something for self-defense like pepper spray or mace.
While giving gifts is nice, you should try to give gifts that are appropriate for the person receiving them. I'm not sure weapons and self-defense items are appropriate for children.
But I want them to feel protected.
I understand that you want them to feel protected, but I don't think that a weapon or pepper spray is the right way to do that. They're probably not old enough to use them correctly, so they might end up hurting themselves. I think you should ask their parents what kind of gifts would be right for them.