where is tinder?

Tinder is in the cave northeast of Earun. :>

im new to hunter island and i heard that there are only limited monsters in caves.now ive beaten any monster i could find so im not sure where to get tinder from now.

Each cave only has a fixed set of monsters that spawn there for you to capture. They never change. So if it was there before it will still be there now. In the top left corner when in caves you will see something like 5/7. That indicates that you have captures 5 of the 7 monsters available in that cave. When you hit 7/7 you have captured them all for that cave. You can still go back later and capture more of them at anytime however. Often each cave has one rare monster that may take a long time to find. I hope that help.

If you have cleared the cave and have not found the Ark you are looking for you can leave the cave and go back to town, then reenter the cave and it will be repopulated. Rare Arks in caves may require you to do this multiple times in order to acquire who you are looking for. Tinder is not that rare, so if you did not encounter him on the first run through, a second run through will probably lead to you finding him.