Technically this is for torchlight 1 TorchED question but if you know how to do it for Guts2 then it should be backwards compatible.

I'm trying to create a new Affix and I know it's possible because 1) You can clone Affixes & 2) I know someone made a mod with 150+ new Affixes and I don't believe for a moment they did that without making new Effects to select them in drop-downs.

It's just really weird that there's no clone or add on the Effects tab.