>>30909645It's the only ability Sylveon can know, besides its hidden ability. And evolving into Sylveon is not affected by time of day.
>>30909556If you do have a Shiny Charm, you should use it. Otherwise it's not 100% necessary. Also, as far as I know, you can't influence nature through SOS.
Most of the Pokemon can call for SOS, but only a few specific ones can't. A Pokemon can call for help as many times as it likes, until it dies. If you knock out the original, the other can call for help too (depending on what the summoned Pokemon is). Sometimes a Pokemon will summon one that can't call for help, or even attacks the one that called. In Salandit's case, it will always end up calling another Salandit, so you don't have to worry. The chain will go on until everything on the field is dead.
Also, the chain counter runs on an 8-bit counter for some reason, and the cutoff is at 255. After that, the counter rounds back to zero. For shinies, you get three extra shiny rolls between 70 and 255. For IVs, when the chain goes past 30 and before 255, you're guaranteed 4 perfect IVs.
