I have done all of them, the legit way. Lulu's Sigil only took me 40 minutes to finally get. Tidus's sigil took about 30ish minutes. Kimari's isn't really that difficult. Rikku's is kind of easy, and fun actually. Yuna's is simple enough. Auron's is pretty easy. Wakka's wasn't that difficult, just rather time consuming. It pays off in the end though.