Crest Location : You may already have this one. Remember when you fought the Chocobo Eater? If he knocked you off the ledge during that fight, you ended up very near to this Crest’s chest! If not, go to the end of the Mi’ihen Highroad, near the entrance to Mushroom Rock. Go southeast and along to the end of the Mi’ihen Oldroad to find this.
Sigil Location : You have to unlock 10 total of Species and/or Area Creations at the Monster Arena. This is essentially done by using Capture weapons to defeat enemies, which Captures them for the Monster Arena. To unlock a Species Creation, you must Capture all of the enemies of a particular species (e.g. all Flans, all Elements, all Insects, etc.). To unlock an Area Creation, you must Capture all of the enemies of a particular area (e.g. all from Besaid, all from Mi’ihen, all from Sin, etc.). You do NOT have to beat them, simply unlock them, and the manager will give you the Sigil.