Spelunky 2

Hundun is the final boss in Spelunky 2. Like many bosses in the game, getting to the boss is much harder than actually fighting the boss itself. Hundun can be found on 7-4, the final level in Sunken City, technically it's own level called Hundun's Hideaway. There are many guides on here telling you how to get to this point so I won't go over it here.

So, right when you start 7-4, you are running for your life. Hundun will be rising up through the level and destroying everything in his path. You must climb up through the level faster than he can destroy it. Unfortunately, there are some very rare edge cases where you basically do not have a chance and will die at the very beginning so you will want to give yourself the best chance possible by having lots of mobility items such as jetpack or vlad's cape or climbing gloves, spring shoes, you get it. Take the quickest possible route to the top of level and wait for Hundun there. Here is a clip of me doing it with little health and no items, just to show that it is possible and what to expect on your climb ->https://i.imgur.com/yYzYddA.mp4

Cool, you have made it to the top. Don't worry, there is no time limit to kill Hundun so take as much time as you need. In fact, if Hundun was poisoned by an arrow on the way up, you can get to a safe spot and wait for the poison to kill him but I'm getting ahead of myself for strats.

Hundun has two heads that need to be killed. The ostrich head has 25 hp and the snake head has 30 hp. He will spit fire balls at you if you're above him and he'll lunge at you if you're below. I will be frank here, if he hits you even one time, there is a very good chance that you will die, ruining your run, so be careful. But technically the fireball only does 2 damage if you were curious.

The easiest way to kill him, in my opinion, is to wait on the second highest ledge that is under the exit and drop sticky bombs on his head. The easiest way to drop sticky bombs is to crouch, press the bomb button, pick it up while still crouched, and then release it while still crouched. If you're on the edge of the ledge, it will pop out and drop just below you. You only need to land three bombs on each head to kill him. Paste is one of the most important items in the game and should always be prioritized, this is one of the many strategies that involve it. If you do not have paste, you'll have to cook your bombs by holding them until right before they explode and then dropping them in the same way. ->https://i.imgur.com/4fahL0p.mp4

If you've run out of bombs or don't want to cook bombs, then we'll move on to strat #2. Hopefully at this point you have spike shoes. They are a guaranteed item you can get from the ice caves by beating the Yeti Queen. Waiting on the same ledge as the strat before and right after one of them spits fire out, you want to drop down on their head, stomp him, and then get back to the ledge. Holding the jump button while you land on any enemy will shoot you up higher than if you weren't so always hold the jump when stomping on their head. Another thing to note is that the damage from spike shoes is amplified the longer you are in a fall animation, this includes slowly falling from a cape or parachute. It doesn't matter how many blocks you fall down, it matters how long you are falling, no matter what speed. With this in mind, using Vlad's Cape or a regular one, it is very easy to hold the glide button down and slowly fall towards Hundun, avoiding fireballs, and then oneshotting him with one super powered stomp. Here is my very sloppy attempt to do just this ->https://i.imgur.com/GqhixO8.mp4

Either way, after killing Hundun, exit the level and the achievement will pop after the credits. If you are going for a Cosmic Ocean run, you should know that defeating Hundun and then going to Cosmic Ocean will not get you this achievement specifically. It's an either/or thing.