This guide is made in a effort to help new players understand the longsword. I will try to explain the best I could.
The Longsword
There are multiple other guides for the longsword, but since I had nothing much to do and want to try to help others, I made this!
The Longsword is one of the most used weapon types in the game. If used correctly, it could be the best weapon out of 14 weapon types. Every weapon could be the best weapon if mastered, but the Longsword’s ability to counter almost every, if not all, attacks makes it a very noteworthy weapon type. I have more than a thousand uses of this weapon and I still enjoy it.
Longsword: Combos
Note:
My keybinds are not the default ones, I set my Special Action key to Q. As it was easier for me. Change it if you wish.
Press Esc > Go to System > Options > Controls > Keyboard Settings and look for Guard/Special Action/Fire Claw
Basic Combos
There are multiple combos you can do with longsword. But the most needed basic ones, in my opinion, are:
– Basic Combo
– Fade Slash Combo
The Regular Combo
Step Slash > Overhead Slash > Thrust > Rising Slash
The Fade Slash Combo
Step Slash > Overhead Slash > Fade Slash
Which basic combo is better?
Both combos give the same amount of spirit gauge needed, which will be talked about in the next section. But, the Fade Slash Combo is faster in gaining it. You can of course keep doing basic moves to fill the spirit gauge fully and deal more damage to the monster.
The Spirit Blade Combos
Spirit Blade I > Spirit Blade II > Spirit Blade III > Spirit Roundslash
This combo is used in order to raise your spirit gauge by one level. But again, theres a faster combo!
Fade Slash Combo > Spirit Jumping Slash > Spirit Blade III > Spirit Roundslash
Doing this combo will allow you to raise your spirit gauge quick. Again, of course there are other combos but this is the fastest.
Doing these two combos, or whatever combo, will, as said, raise your spirit gauge by one level.
Keep doing these combos in order to raise it to red spirit gauge!
Longsword: Spirit Gauge
The spirit gauge is the longsword’s most important feature, as raising it will increase your damage!
Spirit Gauge Levels
The Longsword has three spirit gauge levels: White, Orange, and Red
Raising your spirit gauge to red should be priority.
Try to keep it at red as much as possible! Especially if you wish to do high damaging moves, which will be talked about next.
Longsword: Spirit Helm Breaker
Spirit Helm Breaker is a very high, cool, damaging move, which is performed best when in red spirit gauge. If you use the move when your NOT in red spirit gauge, you will lose some damage!
Please note that, when using Helm Breaker, you will lose one level of your spirit gauge! If you miss the Helm Breaker, you will still lose a level! So use it wisely!
How to do a Spirit Helm Breaker
Do any move > Spirit Thrust > Spirit Helm Breaker
When should I use Spirit Helm breaker?
The best chance for using the Spirit Helm Breaker is when the monster is unable to properly move around (
when stunned, paralyzed, trapped, asleep or claggered/drooling staggered).
Example of a good time to use Spirit Helm Breaker >
Iceborne Added Longsword Moves
With the release of the Iceborne DLC, Longsword alongside the other weapon types received new moves. The Longsword got three moves: Special Steathe, Iai Slash and Iai Spirit Slash!
Special Steathe
Special Steathe allows for you two attacks, Iai Slash and Iai Spirit Slash.
Iai Slash
After performing a Special Steathe, you can perform Iai Slash. Iai Slash became a method of filling your spirit gauge.
If a Iai Slash connects to a target, the spirit gauge will fill over time!
Longsword’s star feature: Counters
The Longsword’s counter moves is what makes it such a great weapon. It has two counter moves: Foresight Slash and Iai Spirit Slash
Foresight Slash
Foresight slash is the main counter move you will be using as it can counter anything. To perform a foresight slash you have to:
Perform any move > Foresight Slash 
This move requires you to memorize the monster’s moveset.One good chance to foresight slash is when a monster is about to do a enraged roar.Successfully countering this will reward you a fill up of your spirit gauge! Which will lead to you raising the spirit gauge level! This method of raising your spirit gauge is the best once you memorize the monster moveset, in my opinion. A failed foresight slash could mean bad news for you, like this example here:
Iai Spirit Slash
Iai Spirit Slash is a high damaging move if performed correctly.
Once again, performing this move well requires you to memorize the monster’s moveset. This move is performed like regular Iai Slash, but instead of pressing LMB (Left Click), you press your Special Action key, Q, if you changed it.
Note:
Just like Spirit Helm Breaker, a improper Iai Spirit Slash will make you lose a level of spirit gauge. A proper Iai Spirit Slash will not make you lose a spirit gauge level.
How do you tell that you performed a successful counter?
Once you hear a little DING! you will know that you performed a successful counter. The following videos shows this better:
Conclusion
I hope this guide helped you in some way! I am not the best at explaining things, but hopefully I did to some degree. I have other 800+ hours on this game and I still make mistakes with longsword, mastering Iai Spirit Slash could take some time.
Better Guides:
These two amazing guides could help you so much more:
Credit to Peppo, a master longsword user, and Arekkz for these videos.
