>>17104961It's okay for that, but to be honest in my experience I found Shadow Sneak to be better since it's no longer resisted by Steel (you only have to worry about normal types and darks).
Water Shuriken is good, but again it really depends on what your team lacks as far as offensive moves go. If you have enough coverage for Ghosts and Psychics, then yeah, I would go for Water Shuriken as a finisher.
>>17104985Scald is okay, but the damage drop from Surf is noticeable. On a frail attacker like Greninja I find more often than not I'd rather be attempting to lethal or near lethal damage than praying for Scald burns to weaken things off. Scald is better used on bulkier Pokemon with less power behind their hits (like Tentacruel), as they can take a hit and continue to spam Scald--eventually they'll get the burn you desire off.
Greninja on the other hand doesn't want things to be on the field very long. He's very frail, and if he can't OHKO or 2HKO whatever he's up against, it's generally better to U-Turn or hard switch out to something more suited to combating your foe.
