Alright, once you're on the second Wyvern floor and have handed in your talon ( you may need lvl75 or 76 to do this, yet to confirm ) you can make your way to SDC2.

Across the grass bridge to the west all all the way to the NE hex of this forest you can find a climb up to progress.

Once you have climbed up here atleast once you can now use the portal in UGH next to Olay and Cobrahn to quick travel to SDC2