that's if you missed the clusterfuck of light events....
if they were around to snag barong like I did then they're already good to go (unless thunderbird is MLB or 3LB)
depends on who you have and what you really want to aim for.
in my case, my light team is more or less settled, so I'm trying to aim for wind and dark myself (but still keeping an eye out for fire) since they're next in line on my strongest to weakest teams...
granted, you'll eventually want to have every element settled, but probably should find out which team is your best and aim for that first.
but if you can spare money, just go for the SSR guaranteed gacha (preferably the kamihime ones) and call it a day.
EDIT: There's a reason why I'm back here 15 mins later... Also could count as tying into the "my light team is my strongest" comment I just made: