League-Start Boss Killer - Ancestral Warchief Champion Ascendancy, Bandits & Pantheon Powers
Ascendancy (Duelist – Champion)
Conqueror
Conqueror is the entire reason this build is a Champion. The fact that your totems, which hit relatively fast, permanently taunt bosses while the boss is in between you and them is so incredibly broken. You literally just get ignored by Izaro, map bosses and what not. On top of that, the node offers some solid Life regeneration, reduced and Less damage taken.
Unstoppable Hero
After debating for a while I opted to suggest something in the guide I generally don’t do myself. I would always pick up Worthy Foe second as I feel very comfortable killing my first Uber Labyrinth without having permanent Fortify and just manually applying it. I think however, generally and especially if you are newer player, going this route, to pick up Fortitude 3rd is just a lot safer. Do note though that if you go this route you need to pick up the Resolute Techniques keystone in order to make sure your Totems’ attacks cannot be evaded! You can unallocate it as soon as you complete Uber Labyrinth and get your last points. So, Unstoppable Hero is honestly just a filler. It grants you stun immunity, a very tiny amount of damage and some armour / Evasion while you have Fortify. While none of that is bad, it certainly isn’t the most exciting of Ascendancy points though! It is required to travel to Fortitude though!
Fortitude
“Click here to permanently take 20% Less damage from all sources in the entire game” sounds appealing, does it not? Honestly, there’s very little to explain or elaborate here. Fortitude is just incredibly solid as you no longer have to make sure you’re using some kind of skill to proc your Fortify all the time and you’re just safe about it as you have it all the time!
Worthy Foe
Remember to unallocate Resolute Techniques as soon as you get Worthy Foe! This will make your totem attacks have 100% chance to hit no matter what anyway, so the Resolute Techniques keystone now becomes useless (and makes you lose damage from critical strikes even, albeit very little). Additionally, 20% increased damage isn’t the worst, especially as this build hardly has any sources of generic damage. It is a pretty solid notable altogether and, as mentioned, something I personally would pick up second just to have more damage while leveling. If you feel super comfortable killing Uber Izaro while being more squishy, feel free to follow that route!
Bandits
Here’s a special one! I think this is one of the only builds in the game that actually wants to help Oak! Oak gets you Life Regeneration, Physical Damage Reduction and some extra Physical Damage. All of these are incredibly useful against Izaro so you take them any day!
Pantheons
Major Gods
Soul of Lunaris is probably your best pick. No one has ever said no to some extra Physical Damage Reduction, especially when you want to farm a boss that only does Physical Damage.
Minor Gods
I would recommend Soul of Gruthkul here as well .. It’s the only source of Physical Damage Reduction on the minor Pantheons! More is better here!
Upgrading your Pantheons
Whilst upgrading your Pantheons never hurts you, it’s not that important for this character. If you have nothing else to do at some point, sure, why not, but it shouldn’t be something you focus on or spend a lot of time on.
Pantheon powers can be upgraded by using 
Divine Vessel in the Map Device while you are activating the particular Map that contains the boss you need. Once you’ve killed the boss and captured his soul, you need to deliver the Divine Vessel, which’ll be filled up in the map device, to Sin in Oriath.
Main Page / TL;DR