


In order to face the Thawing Dragon Lord you need to go to the basement in the Falcon Bastion. In the basement you need to break a wall with a melee weapon in order to get access to the other side. If you walk east you will run into the NPC, Crowned Tree. You need to speak to him and say Hi and complete the dialogue in order to gain access to kill the Thawing Dragon Lord. Next you'll need to find a Frozen Dragon in the wall and use it. Using this will allow you to face the Thawing Dragon Lord. He takes a while to kill as he apparently has 25,000 hit points. From my understanding you can kill this boss as much times as the wall will repair or freeze-over so I've asked around and people claim it can be 5-10 minutes.

https://tibia.fandom.com/wiki/Falcon_Bastion
If you'd like to watch a tutorial I'd recommend (I couldn't find a tutorial in English I'm sorry)
https://www.youtube.com/watch?v=oZM_YNywb_E


