http://thpp.supersanctuary.net/wiki/RinBase stats:
HP:90
Atk:95
Def:80
Spd:95
SpAtk:70
SpDef:90
Abilities: Intimidate/Flash Fire
At first glance Rin is mediocre in every way, 4x weakness to water means aqua jet is her bane and no really outstanding stats. Ya, that impression is wrong. First of all with intimidate and a sandstorm boost rin effectively has 120/135 base defenses, she resists ghost, steel, nature, and can have fire immunity and only has 2 weaknesses, add that to a useful attack stat and decent speed and you have an amazing defensive pivot.
LOLOLOLOL YoukiRin @ Leftovers
Ability: Intimidate
EV's: 252 Hp/@252 Def/4 spd atk or spdef
Nature:Impish
-Wilo Wisp
-Wish
-Detect/roar/crunch
-
FlareBlitz/Fire punch
Usage: This set is good at what it does in or out of the sand, and what it does is flat out stop physical sweepers while providing wish support. Momiji used tailwind?Youki used Swords dance? Sendai used curse? Ya Rin does not give a damn, she can hop in wilo wisp/wish detect/roar/flare blitz/crunch and leave that poor little sweeper either crippled or dead. Roar lets you get spikes damage on predicted switches and wish is just good team healing. This is probably the set that best abuses her stats and typing.
Counters: Water/flying puppets and attacks in general force Rin out, though she can still abuse intimidate on threats like A Suwako with decent prediction (and luck) via pivot switching. However she flat out cannot come in on A Reimu Attack Yuugi or the Komachi forms. Plus due to her healing being wish based she really hates spikes/toxic. She also cannot do much to a wall that resists Flare blitz/Crunch aside from tossing a burn on it.
Support: Sand + team mates that can Rin's weaknesses and aromatherapy/heal bell support can transform Rin into one of if not the most ridiculously difficult to break down lonely pivots in the game.
Options: Rin has a pretty huge movepool that can allow her to play everything from special pivot to cursing E killer, the above is simply her mainstay set. Feel free to play around with her nifty movepool.
TL:DR: Try the kitty, if only cause her shiny sprite is awesome.