And I burned 100 scrolls in Kage, getting my 4th rare and still no Kazekage.

Already have Bee, got Mifune and Darui... I think the game want me to go lightning, that's like all of the lightning main related rares... (Ay is super I believe). I bet I'll get Chojuro next for the bloody sword set.

I'm a wind main and I never change (for 7 month now, I wonder how many people can say that, not for exam, not for SA, not for GNW, never change), so Kazekage is kinda what I want the most...
At least in Sage, Sage Naruto is guaranteed with 180 pull, I'm not entirely sure if guarantee (i.e. no repeats until full set) exists in Kage.... I know it doesn't for summon and Kage have almost as many rares as there are gold summons.

At least I have Mei the Bae... and that works decent as a girl for wind main...

Well, at least you got him before your completion, imagine getting 20 frags instead....
Now you are closer to 4 star XD

Tendo is a super rare, unless you are willing to spend money, you aren't getting that anytime soon(I think 400 as opposed to 60 for rares). Don't use scrolls on two different treasures, because the counter for rare is independent for each. As it stands, you should either do only Sage until you get Sage Naruto or do only kage, tendo is not worth going for.