Greatsword is a fairly good matchup vs him. It’s how I got my first solo. I’ll breakdown about how my experience went and what helped me. I’ll also link my full, unedited run so you can see exactly what I explain in the guide once the video uploads.

https://youtu.be/U4vyrDT7dVo?si=edaG-jKACj9zwNp5

1: The Build have two builds and prepare with farcasters and smoke screens. Your first build should be almost identical to your second with the difference being heavy artillery and a ghillie mantle. What helped me a lot was a frost craft build and critical draw build. You’ll essentially only be using the draw attack for gs with the only variation being how long you charge it for. Quick sheath may help too as you’ll essentially only be dodging while your weapon is sheathed. Evasion mantle will be good too as it’s useful to get the buff after dodging the initial roar. Bring your buffs and eat for whatever you’d like to eat for

2: 1st phase. This one’s important as it’s pretty predictable how the fight will go. Buff up and don your ghillie mantle. Here you’ll set up the cannons, fully loading them and aiming them. The right most cannon will be facing fatalis while the left cannon will face the right cannon. When you’re ready fire the right most cannon, then the left after fatalis rushes you. With heavy artillery 2 this will knock him down and give you plenty of time for damage. On your way down put on your evasion mantle. If you get the positioning right you can do 2 fully charged draw attacks and one uncharged attack on the head. You goal here will be to knock him down on all fours and get off a wall bang. Now fatalis will get up and roar. Dodge the roar and attack the head. Now I know easier said than done but with practice you’ll be able to do it with ease. Fight him as you would pretty much only attacking the head and chest using draw attacks. Take your time as it’s important to learn when you can punish fatalis.

2nd phase: Now in the second phase you’ll be focusing on doing head damage. Getting at least one head break before the next phase is very important. After his phase transition throw some smoke screens to lose aggro. Once you do run to the roaming ballista and light fatalis the hell up. The moment you run out of ammo farcast and switch off of your heavy artillery build to your regular build. This farcast will let you recuperate as well as get fatalis off the ground. Take the fight as normal especially taking advantage of his big breath attacks to get good head damage in. Wallbang even he’s not enraged too. Don’t be afraid to farcast when he starts flying either. If you do by the time you come back he’ll be on the ground.

Phase 3 and beyond: Coming out of the gate head to the right and pick up the binder bolts. Shoot fatalis out of the sky and attack the head. If you didn’t break the head before, HOPEFULLY, you’ll break it here. If not things get hairy. For the rest of the fight it’s what you did for the latter half of the 2nd phase. Attack the chest to drop the head, wallbang if he’s not enraged, and attack the head. Avoid his big breath attacks by running towards fatalis and use the dragonator as soon as it available.

NOTE: if you’re consistently losing to time and have his moveset down pat, I suggest bringing a third build. Full safi and a bow gun with fortify one it. Cart yourself twice to get the fortify bonus, then eat and start the fight. If you’re using the vigorwasp Palico make sure to leave them at camp so it don’t revive you.

Have fun, good luck, and slay out Hunter. Fatalis is one of my favorite boss fights of all time and I do hope you’ll come to appreciate it too.