Undertale is, in a word, a masterpiece. It has stunning gameplay, great graphics, not to mention almost everything you do matters. Another thing is it has multiple endings, and after I finished the pacifist route, I took a little break from this game, contemplating what else I would do. One day my friend asked me if I was going to do genocide. I answered yes, as I had heard many things about this route, not knowing what I just did. There are many reasons not to genocide in undertale, but there are better reasons to do it than not to, as the genocide route is what most fangames revolve around, the biggest part being the sans fight. This fight is exclusive to the genocide route, in which you must kill every single monster, which, to put it simply, takes a while.
After killing everyone in the ruins, snowdin, and waterfall, I came to the room before undyne arena, (I can't remember what that room is called) where I fought Undyne the Undying. It started out as most "bossfights" in genocide, where one would just start the encounter, and one-shot them before they even have their first turn. But Undyne was a different story. I hit her, her health went to zero, but, she didn't die. Instead, her determination to live let her reach her final form, Undyne the Undying. This fight was way harder than the normal battle in pacifist or neutral, and I died a lot. Each hit decent hit does about 1300 damage, but I think it's possible to do up to 1700 damage. She has 23000 health, (yes I searched that, on the undertale wiki) so she's not going down without a fight. Fortunately, on probably the second day, I did end up victorious, and moved on to kill everyone in hotland, "fight" mettaton NEO, which, depite a different form, was just like all the others, where you one-shot and move on. Then I came to last corridor, where my "bad time" truly began.
After saving in the last corridor, I walked through about halfway, and standing waiting for me, was Sans. After giving me a short speech, the encounter started, and I almost died on the first attack. The only reason why I didn't die is because I had seen this fight before, so I knew what to expect, (not that I could do much about it) and what I expected was, in a word, pain. After that attack, I attacked with my knife, and missed. Yeah. He can dodge attacks. By the end of the first day of attempts, I was not even halfway done with the battle.
The next time I attempted this battle was 1-2 weeks later, as I would normally be playing fortnite, my current favorite videogame of all time. Sometimes however, I would get bored, as nobody I knew was online, so I would boot up undertale, and give the Sans fight another go. After a couple warm up runs to get un-rusty, (as a couple weeks does something to your skill at almost any videogame) I had reached the halfway point, in which Sans spares you. As I said before, I knew about this fight, so I knew if I took his mercy, he would betray me and kill me. So I swung and missed, and he started showing me his TRUE power. A few attempts later, I had to stop, as it was time to eat, and by the time I came back, my friends were online in fortnite, so I decided to call it for the day.
A few days later, it was time again. This day was not much to talk about, I made it farther into the fight, yes, but nothing really noteworthy, although, I'll just say this phase is pretty hard, but if you have played any of the fangames, (which I haven't, but I heard stories and have seen people play them on youtube,) and come back to this fight, it'll seem REALLY easy, no joke. One thing that is nice about this fight is there is an attack where he slams you against the wall, and you are supposed to have a good enough reaction time to jump up before bones come up where you were just slammed. However, there is trick where if you hold all the arrow keys, you will jump up as soon as you get slammed, so if you do this, there is no way you can get hit. (Unless you don't start holding down the arrow keys fast enough in some of the later versions of this attack.) (This trick could probably work on Nintendo Switch, if you use the Joy-Cons, which have directional buttons instead of a D-pad)
A week later, I knew I must grind sans again. It started out normally, dying a lot on phase 2, but then, one attempt, I didn't die on the part where I died a lot, and made it to the final attack. Now, I was at like, 12 HP or something (max HP for this battle is 92,) so I knew I would die, but I didn't give up. I played through that attack until I died, so I would have more experience on it. A few attempts later, I was back. The final attack is hard, I will say that, with a small slamming part, then you weave your way through some bones that are going up and down, then there is a part where you are falling right, and you need to go through some bones, then you get slammed against the wall, which after jumping from, you need to have good reaction times as you jump from bones that appear from under you, and then, well then, you will die. The final part of this monsterous attack is a circle of Gaster Blasters, which blasts increasingly faster, so you first have to run in circles close to the center, then closer, then practically in the center. My friend said the best way he can do it is by having at least 40 HP at that section, and just tanking the damage. Thats how hard it is. I died there quite a bit, before I had to leave. I knew, the next day I attempted this, I would prevail.
So you know the speech Sans gives you when you are halfway? Well he only stops doing that once you spare him. So by this point I was a little bored of skipping through all that text, every single time. So I decided on my first attempt of day 5, I would spare him not just to skip the text, but also to see what he says when I do so. After selecting mercy, then spare, he said something along the lines of, "..." "you're sparing me?" "buddy" "i know how hard it must be to make that decision" "to throw away all you've worked for" "come here pal" (Sans doesn't have very good grammar) (also the reason why there are so many "s is becuase each time you press Z, the text advances to the next set of quotes) Then he straight up killed me, and said, "geeeeeeeeet dunked on!" "if you really are my friend," "you wont come back" On my next attempt, I... won. I'm not kidding. THE attempt after I bored of his speech (after sparing him and coming back he says "listen" "friendship" "its great right?" "lets quit fighting") I literally won. So I got to the final attack, (Here I was "afk" in fortnite and my friends were in my party, so I could talk to them while grinding snas) my heart was pounding, and once I was done, I was kind of shaking, not gonna lie. (Hey, you try this battle and see what happens) So I did the stuff to get to the gaster blaster circle, by this point I wasn't expecting much, but was excited anyways. The strategy for this attack is to have a decent amount of health, (I think I had between 12-20 HP) to get gradually closer to the center while running in circles, as the blasters do gradually speed up, so in order to not die, you need to inch your way towards the center, and the reason why you don't do this from the beginning is so you don't accidentally run into the blasts from the gaster blasters in the early part of this attack. After you are done with this attack, feel free to yell in truimph as he slams you around the box, dealing one damage each time, (this "attack" can't kill you, don't worry) after which he gets tired, falls asleep, and, to put it simply (and not spoil anything more than I already have,) you kill him while he's asleep, thus winning the battle, and moving on to Asgore and Flowey, who you one-shot, and the genocide is over. Everyone is dead. You win! The only thing left to kill is the game itself, which you do, (...) the end. (I hope 7 paragraphs is enough...)