Mechanics:
For Boss Rush, you can unlock the evasion skill on you skill tree, which you should normally have locked. It is a very good, no cd and cheap on stamina pve iframe. :D
0:00 Beginning
He always starts off by stunning you, bringing you to around 30% hp and slowing you. You can V this but it’s not really useful on c7 since you barely do any damage to him before you remove his dp buff. Also, you might need your v since he likes to cc you even in iframe. On lower difficulties I do like to V it though to get better times.
0:25 Remove the dp buff
After the stun, he will do 1 attack and after that he will always shortly disappear, the message: "You feel a chill down your spine" will appear and when he reappears, he will glow for around 1 sec.
Cc him (stiff/stun/float) when he reappears to stun him shortly and remove his dp buff. On C7 he does this attack 3 times, after that it will not appear again.
All his attacks are pretty slow and telegraphed so just dodge them and back attack him in between as much as possible.
After he jumps back, he either does an attack with a huge half circular red indicator. Move behind him to avoid being slowed and get free back attacks in. The other possibility is him doing an attack, where he jumps onto you and starts eating the ground. Definitely avoid being hit by more than one tick of that since it does a ton of damage. You can iframe behind him and get some free back attacks.
When he jumps up in the air, you have a few seconds to maybe regen stamina and then iframe when he lands.
1:30 80% HP
Once he reaches 80% hp, you will see a time stamp pop up. He will jump up in the air and always reappear at the same location. Just look for the side of the arena where you can see light coming in and position yourself to be ready to back attack.
He will start charging a “powerful attack”, just back attack until the message: “Sangoon failed to gather energy and couldn’t keep the posture” appears. He will then still do an attack, try to iframe it but don’t worry if you get hit, it won’t kill you.
2:06 70% HP
At around 70% hp, he will do a oneshot. It’s pretty easy to see, he will turn untargetable and a huge red indicator with the message: “Khahahaha! I shall tear you to pieces with these claws!” will appear. Iframe and pray to the lords you don’t just die anyway.
2:28 60% HP
At 60% hp, another time stamp will pop up and rocks will start falling from the ceiling. Just avoid the red circle indicators.
He will then soon jump in the air and the message: “I shall kill all who walk on two feet” appears. Hide behind one of the big rocks to be safe from the oneshot.
You don’t have to spam iframe behind the rock like me, I just did it bc he still knocks you back and then stuns you even behind the rock and then you will get damaged by the second attack. It won’t oneshot you so don’t worry if you do get stunned.
3:19 50% HP
At around 50% he does the same oneshot as the one at 70% again.
3:54 40% HP
The message: “The Tiger Palace begins to shake and rocks start to fall” appears. Now around the edge of the arena, rocks will start falling down in intervals. You can see when they are about to fall by the crumbling ceiling. Be really careful now and don’t let him bait you to the edge off the arena, when they are about to fall down. They cc even through protection also it’s always a bit of a gamble to iframe. You are very likely to die or have to v If you get hit by anything. Also the hitbox seems a bit bigger than indicated so just be really careful and try to stay in the middle of the arena.
Also look for a big red circle sometimes appearing right in the middle, this circle means a big rock will soon fall in the middle. The circle disappears before the actual rock falls, then you will see the ceiling crumble in the middle and then the rock will fall. Also move out of the way of that.
5:36 20% HP
Sangoon will jump up an the message: “I am the ruler of the Tiger Palace of Taebaek, Sangoon!” appears. He will now stand still in the middle of the arena, charging a oneshot, while there’s rocks falling from the ceiling and red damage zones appearing all over the place. This is a dps check, if you don’t kill him quick enough, he will do a fairly long oneshot. But you can dodge it by spamming iframe and using v if needed. I think you don’t have to worry too much about the red damage zones, as they don’t cc but be very wary about the rocks falling, as those do cc, also through protection. There will be small rocks falling from the ceiling but also sometimes the big one in the middle.
6:17 Dodge the dps check oneshot
The oneshot happens once he puts his feet down on the ground but be careful, he stuns before using the oneshot so if you don’t dodge the stun as well, you won’t be able to v.
I am not sure if SA, FG or pve iframe work to dodge the stun. I think I iframed it with a normal iframe.