Sailor is realllly good. I'm using this team right now http://i.imgur.com/TaiQArv.jpg?1
I have had sage naruto and bee die while my enemy was full hp on all ninjas and I came back and killed them with just sailor and earth main cause their combo damage couldnt kill sakura and you are forced to combo her at some point cause you can't combo earth main. she is probably my favorite ninja ive used so far

As far as the immortal team goes, I have seen
Sailor Sakura x x
jigokudo water main kimimaro
x x x
haven't tested it myself but see lots of ppl on taiw*e it