Alright, as for Kaiser Wolf: north section just before Dragon's Lair/Wyrm Nast, it's at the right bend area. Before you find him you have to kill Rare Lindbur Wolf.
To make Lindbur Wolf spawn you need to go to Shimmering Horizon and get a chain combo of 20 regular wolves. He will appear then. Go back to the Corridor of Sand and find the Kaiser Wolf.
For Dustia, you already know the correct area. Dustia will only spawn when any character of your main team has less than 10% HP.
Good luck
againstall has invadedBECKY = 10/10