Once you're back at Southern Tolbas Forest you will want to run past town and down over to the "X" on my map:
Over here you will want to kill the Tiny Arachna's for an Arachna Poison Sac. Once you have the Poison Sac return to town and turn in your quest to Illos.
After you've done that you'll want to head east again following the southern path towards the yellow arrow on your map. Along the path you will find Giant Rakeclaw Frillnecks. You'll need to kill 12 of these for your Frillneck Hunt quest.
While you're killing the Rakeclaws continue east to the NPC with the yellow arrow over his head, Lepios. Refresh your supply of quests at him and now kill any of the following creatures that you run into:
All of those creatures have a chance to drop Contaminated Fluid Samples. Once you get all of the Contaminated Fluid and killed all 12 Rakeclaws head back up to Lepios and turn in your quest. After you've turned in your quest to Lepios head west back to Geolus and refresh your quest.
After you turn in your quest to Geolus head back to Verteron Citadel. At Verteron Citadel you will want to Refresh your quest. After you've done that take the Teleporter back to the Sanctum. Once you arrive in the Sanctum you'll want to mark the location of Dimos on your map.
It is a long run in order to get to Dimos. Once you arrive, talk to him and refresh your quest. Now you'll need to head to Jumentis. He can be found further north in the Protectors Hall. In order to reach him in the Protectors Hall you will need to take the Elevator up to him.
Talk to Jumentis and refresh your quest. Once you refresh your quest you will want to head down the elevator and east over to Quintus.
Talk to him to continue your quest yet again and then head far north to the Lyceum. At the Lyceum you will want to Hygea for Yustiel's Tear. Once you have the tear you will want to talk to Geolus.
Now It is time to head back to Tolbas Village and turn in your quest to Leto. If you kept yourself bound at the Obelisk here then you can simply use the Return ability, otherwise you will have to run to the Teleporter then take a flight here.