Before you start your Ultimate run, make sure that a few things are absolutely clear in your mind.

• This mode will show you no mercy and will test your patience a LOT.
  
• Use whatever you can to your advantage to win, exploits, metagaming, cheesing fights, everything
  goes, throw your moralities out the window for this and embrace the madness.
  
• You HAVE to play chanter if you value your sanity.
  
• You WILL have to exit the game to the main menu and reload frequently to avoid the save file
  getting deleted. Whoever calls this cheating is a lunatic.
  
• And of course, you should have beaten the game before to know what to expect generally, how the quests and story goes, and a good understanding of mechanics.

Chanter is the go to class for this challenge due to their unique ability to singlehandedly destroy large crowds of enemies as well as bosses. There is a lot of leniency for races and stats, I personally played human, but aumaua and moon godlike would also be excellent choices I think.

Attributes: You will need maxed out Might and Intellect for the best damage output, you can dump dexterity as low as possible in order to get some Constitution and Perception. These numbers are very variable and largely don't matter as long as you have the Might and Intellect sorted. I personally went 18/13/3/14/18/9

Skills: you will need a good amount of mechanics, traps will provide a great source of XP early and let you discover hidden objects throughout the run as well. Getting 4-6 lore will also be helpful for scroll usage, you can boost it by various things later to 10 if you need to. A little bit of survival for the healing bonus or the accuracy bonus when resting. Stealth can be extremely helpful early game and at specific points in the game, so consider that as well - you can always respec if need be.

Talents: Brisk Recitation is needed for maximum damage output, remember that you are alone and you will have to do everything yourself. Doing more damage also results in fights ending quicker and therefore less damage taken!

Spells: Your summoned phantom from 'But Reny Daret's Ghost, He Would not Rest' will carry you in the early game pretty much, it will almost always stunlock one opponent while you make sure to stay as safe and healthy as possible.

Character background: I picked Drifter for a bit of early game stealth and mechanics, but I'm sure many other background would work. Living Lands is probably the best for the extra Might bonus.

Chanter is at its weakest in the early game, and so your goal is to push to level 9 as fast as possible so you can learn 'The Dragon Thrashed, The Dragon Wailed' phrase for all your damage needs. I will list the talents and spells that I think work great or are mandatory.

Talents

• Gallant's focus: Things won't die if you can't hit them
  
• Weapon and Shield style: Deflection bonus and evens out your terrible reflex stat from dumping Dexterity
  
• Superior Deflection: Even more deflection
  
• Body Control/Unstoppable and Bull's Will/Bear's Fortitude: Getting cc'd is the easiest way to your grave.
  
• Veteran's Recovery: The passive heal scales with Might, and will contribute a lot to your survivability.

Phrases

• Level 1/2 Phrases: Grab whatever you like, mostly irrelevant while you are only looking to summon your phantom.
  
• Level 3: The Dragon Thrashed, The Dragon Wailed This phrase defines chanter, it will be almost all your damage output.
  
• Anything above 3: Doesn't really matter, you can grab the 'With All Your Strength Slay the Beast' for dragons, if you like.

Spells:

• Level 1: But Reny Dharet's Ghost, He would not Rest, White Worms Writhed in the Bellies of the dead. - The phantom will be your best friend until you get your dragons.
  
• Level 2: At the Sound of His Voice, His Killers Froze Stiff: AoE paralyze, nuff said
  
• Level 3: Oh, But Knock Not on the Door of Urdel and Gurdel: big goons to tank for you
  
• Level 4: Their Champion Braved the Horde Alone: This can be very useful due to the damage reduction
  
• level 5: Called to his Bidding the Ancient Instruments of Death: your lategame killing arsenal

Story Talents:

• Side with the Crucible Knights for Second Skin
  
• Focus the machine on yourself for Gift of the Machine in Heritage Hill
  
• Side with the glanfathans for Wild Running
  
• Rescue the Fangs member from the pale elves for Blooded Hunter
  
• Let the bard eat all the birbs for Song of the Heavens
  
• Side with Galawain, for Galawain's Boon
  
• Play some dice in the Stalwart Inn for Dozen's Luck

With all the tips in mind, it's actually time to start the challenge! I'll try and list a basic route so you can plan ahead as well.

• Start out as normal, get to Gilded Vale and do all the basic quests. At this point you will be very weak and most things will overwhelm you. You might need to do some ranged weapon pulling and kiting shenanigans while you build phrases to summon your phantom. The most important thing is to get to level 4 and grab the ice resist cloak from the Gilded Vale inn's 2nd floor. Amass enough gold to purchase the summoning item from the blacksmith. You can get a ton of XP and loot if you sneak into Raedric's Hold and mess around there.
  
• At level 4, you can attempt to claim Caed Nua. Sneak your way to the main hall, where you will face the first very difficult fight. You need your ice resist cloak against the ghosts, and you can use your summon to distract them while you get in a corner so you only need to fight them one by one. Sneak down to Maerwald afterwards, past the spiders. By far the easiest way to deal with him is to clear the xaurips on the right, pull Maerwald, then pull the beetles in the south room, run back to the room you cleared, and let them kill each other. Finish off whatever is left after they fight and you have yourself a fortress.
  
• You will have a lot more freedom after this, get to act 2 without doing anything else. You will still be very low level, but Defiance Bay is full of easy quests, a lot of them requiring no combat or very little. Make sure you grab the free summon item from the hidden object at the theater. Do everything you can in the city, it should get you to level 8-ish. After that, head to Dyrford, again skipping most things in the wilderness because they are too dangerous. You can also head back to the Gilded Vale area to finish up any quests you have left, Kill Kolsc or do the Temple of Eothas dungeon. Getting to level 9 can be a bit of a scramble.
  
• After level 9, you have become a powerhouse, and the rest of act 2 and 3 will pose very little threat to you. Proceed as normal, and get to the White March as late and on as high a level as possible. You can do all bounties from the Warden's Lodge for an easy 2-3 levels. You should be level 14-15 by this time.
  
• The White March will mostly be easy as well, there are only key, powerful items to acquire. Complete the questlines until you have only the largest challenges left for the Ultimate.

The boss fights:

• Sky Dragon: By far the easiest, if you have your spectral weapon spell, you will have absolutely no problem with the boss.
  
• Ice Dragon: Much harder, you can try using confusion scrolls, or summon items to distract him. If all else fails grab your Boots of Speed and run circles around him.
  
• Adra Dragon: Extremely easy, run straight to the east and dispatch his goons until only the dragon is left. He's so massive and clumsy that you can run around and you'll never get hit while your phrases whittle his HP down.
  
• Concelhaut: Should be an easy one too, pull out of his room and watch your dragons eat everything while you stand in the corner.
  
• Llengrath: This is an insane fight, you will need excellent positioning and preparation, the tactic that worked for me is running up to the bridge in the north of the arena, in a position where the flying dragon was spitting on me, while the grounded one was directly behind it. This way my AoE cleaved both of them while I was essentially only tanking one. The small shield called Black Sanctuary is insanely valuable in this fight, giving you a whole minute of breathing time and invulnerability while your phrases can freely do damage. Best of luck with this really...
  
• Thaos: Not even worth mentioning, he'll be a joke after all the crap you've been through. Well done if you made it!

Some extra tips and thoughts I guess

• Make use of NPC leashing ranges, you can separate them by repeatedly pulling and disengaging them in combat. Very useful for early game. Pull with ranged weapons to maximize distance.
  
• Always prepare with the quickslot items you need, the best food, and resting as well as brothel buffs before big fights.
  
• Levels matter a lot, if something is too hard you can often go back in just one level to clear it.
  
• Gear also matters a lot, don't even attempt any of the bosses on the Ultimate checklist before you have a wide array of gear options.
  
• Generally it's best to use the heaviest armor for maximum DR value, a hatchet for extra deflection, and a small shield so you don't lose any accuracy - however, always be mindful of the fight you are up against, and change your equipment accordingly if it helps.
  
• Combat movement speed is king - Most all melee opponents can be cheesed by running around them with Boots of Speed if you have high enough Intellect for your dragons to reach them. Use the extra AoE range amulet and an Overseeing ring for an easy added 30% bonus, very useful for dragons.

Thank you for reading this guide, I probably forgot a few things so feel free to ask while my memory is still fresh of this challenge. Here's my character page after killing Thaos for reference.