Upon arriving at the amphitheatre you’ll meet with Triss or Iorveth (depending on your previous choices). If you picked the former you will also have to kill two more basic guards. Make sure you have all of the potions, weapons, and armor you need as you’re about to hit the final parts of the game. Once ready, head inside and listen to the discussion between the three kingdoms.
Regardless of your choices, Sile will be charged with treason and will retaliate by summoning Saesenthessis the dragon. Dash up the stairs and into the tower. The stairs will start to crumble, forcing you to keep moving quickly. However, don’t blindly run forward, as the dragon will poke its head out and attack with its fire breath. Keep an eye on the floor and the walls and you should make it to the top of the tower without much problems.
Sile will make a grand speech, however her teleportation device has been tampered with. Free her to gain some more info about Yennifer, or simply wait and watch the sorceress explode into meat chunks. Either way, Saesenthessis will bust through the wall and attack.
Keep Quen up at all times. This will negate the fire damage and even protect you from two or three melee attacks. Be defensive for the most part as the dragon can hit for almost 100 damage (before your armor bonus is added). If you made time to build the Zekkikanterment or locate the Addan Deith, you can do some serious damage with your strong attacks. Wait until your foe breathes fire and you’ll be able to get in a two or three hit combo.
After half of its life meter is down, complete a quick time event and head to the roof for the second part of the match. The strategy remains the same, but this time the dragon has a full 360 degree circle to attack from, requiring rolling much more often. Always wait for the dragon to use its breath attack, allowing you to effortlessly block with Quen and deal heavy damage from your silver sword. Once its life meter is nearly depleted, get ready for once last quick time event. Afterwards, you must decide what do with the dragon. If you sided with Philippa earlier you will break the curse on Saskia. However, if you went for Triss your only options are to kill or walk away from the dragon.
You’ll meet with Triss or Iorveth again. This time kill off the remaining bandits that are pillaging the ruins of the city. You may part ways with one of your old companions at this point and march off for a final confrontation with Letho.
You can ask the fellow witcher about the whole truth and Nilfgaard’s schemes. If you like what you here you have the option of letting the giant go free. However, you can also opt for one last duel.
If you pick the latter option you will fight Letho one-on-one. He fights nearly the same as the encounter in chapter one, however this time you’ll need to take down his own life bar. With so many more skills learned, killing Letho is much easier than the previous fight. Keep Quen up and use Yrden to trap him in place. If he puts up Quen, avoid attacking him directly and wait it out. Aard is still a great means of keeping him stun locked and unable to hurt you properly. As long as your steel sword does 45 or more, putting Letho down with strong blows will take little effort. Upon concluding your business with Letho, you will complete the Witcher 2 through Iorveth’s story path.