it does seem rather complicated at first, but the overall thing to go for is Atk increases over anything else.

not saying other increases wouldn't help (cause i know HP does for teams like my fire and thunder ones), it's just that atk helps the most.

it's why i got Slephnir (currently gives 55% wind atk and drop rate up), over Jabberwock (50% more wind atk along with ability damage up). Not just cause my wind team doesn't have many wind ability nukes, but it's also cause my grid has a ton of SSR wind items on it, with lv125 weapons to fill a few holes for the time being