It's a bit hard to give specific lens recommendations as you don't specify your natural eye color and if you need prescription lenses or not. ^^" Universally popular brands are Geo and EOS, to name a few. But depending on what type of circle lenses you prefer (big, small, vibrant, costume-y etc) for your cosplay you might want to check other brands as well. I.Fairy usually has bright and big lenses that look good for cosplay.
One of my favorite lens shops (that I've bought from for years) is LensVillage
, mainly because of the good customer service, safe lenses and because you get free international shipping by buying 2 pairs or more! Shipping costs are a huge deal for me and I always try to get free shipping if possible, haha. If you decide to buy from LensVillage feel free to use my discount code SAMURAI15 to get 15% off your purchase. ^_^
I sadly don't know the character (otherwise I'd give you direct lens recommendations) but I'd recommend you take a look at my circle lens reviews (I've reviewed a lot of green lenses!) here
and see if there's anything there that you like the look of.