Don't trust the version of the mod which is precised for this review as I am using the last version, available only on planet Minecraft at https://www.planetminecraft.com/mod/172164-dynamic-sword-skills/ ; The last version of the sword skills API can oddly be found on curseforge with an unofficial fork under the name "Dynamic Sword Skills 6.2.1" as it is the version of the mod this API is meant for (the mod's API is also more officially available on planet Minecraft at https://www.planetminecraft.com/mod/sword-skills-api/ under the right name this time)

What is it ?

A mod which adds Zelda-inspired custom melee Combat Skills , alongside a Z-Targeting system to lock on enemies (this auto-target is even required for some of the skills to be used);

What does it offer ?

Special abilities for melee weapons and swords, which can be found randomly by killing mobs or looting vanilla structures, and can have special effects which increase in strenght after each level gained.
The Basic Technique is the base skill required for a couple of others, it allows you to Z-Target enemies to keep them locked on while you can still see them (there's a specific keybind set for that, as well as a second one to switch from target to another target near); Any solid block in the way will prevent the player from locking onto entities , but I find it a bit annoying that even transparent ones such as glass stop the targeting move.

Here is a full list of the other skills available (SPOILER) :

For Melee Weapons in general :

-The Armor Break
This attack is automatically performed after holding the attack button after attacking (attacking but keep the button held will perform this move), the second hit will pierce the armor, dealing heavy damage even to protected foes
-The Ending Blow
Requiring Z-Targeting, this move allows to deal more damage to an enemy by pushing forward with another hit after attacking at least twice, even granting bonus experience if it ends up killing the foe; it can be exausting, so be wary of using it on enemies which may outlive it
-The Parry
Not this is not the 1.7.10 parry mechanic but a different one requiring more skill, as you have to step back twice before blocking perfectly while the enemy attacks you with a melee weapon/item for the defense to actually register and negate all damage you should take, and when it does it even has a chance to disarm the opponent
-The Spin Attack
Already present in older Zelda games such as The Legend of Zelda: Ocarina of Time and quite famous (probably the most well-known skill from the game series in that whole list), you have to press both the key to move left and right, the first one pressed will determine the spin's direction; this attack is especially useful when standing in the middle of hordes of weak enemies like silverfishs as it allows you to spin around twice to kill them all
-The Super Spin Attack
Primarly found in The Legend of Zelda: The Wind Waker, this skills works on top of another skill to allow you to maintain the spinning move by pressing attack again and again (just kind of spam the attack button it usually works)
Requires the Spin Attack skill in order to work.
-The Sword Break
A special form of parrying, which will damage the weapon an enemy is attacking you with if you move step forward twice before blocking perfectly as the attack would normally hit you; instead, the attack gets blocked and the enemy's weapon starts breaking (repeat a couple of times to end up with a weaponless foe)
This skill is definitely much easier to perform that the Parry but a bit less rewarding.

For Swords specifically :

-The Back Slice
Present in at least The Legend of Zelda: The Wind Waker and used notably to remove the armor of Darnuts from the strings which tie them from the back, it relies on Z-Targeting and is probably the most satisfying to use when it does work, as after holding left or right then moving before double tapping the forward key you will run around the enemy, and if hit right, will deal more damage with a chance of removing their chestplate (unfortunately if your default speed is altered you might end up too far away from the enemy you were meant to hit after using this move)
-The Leaping Blow
It's basically a stronger critical hit, needing you to hold block before jumping and attacking, which when performed deals damage in a small area around you (which will damage creatures standing near)
-The Mortal Draw
Needing Z-Targetting in order to be used properly, this samurai-like move works by keeping a hidden sword in your hotbar while being empty-handed and holding the block key -> when the enemy does attack, attack at the same time, effectively cancelling their attack while automatically drawing your sword to deal twice the amount of damage
-The Rising Cut
This acts as a sort of reverse critical hit, being a move which requires you to sneak before jumping and attacking afterwards (before falling down, not while falling); this lifts you up and the enemy into the air, which lets you attack once more or let it take fall damage
-The Sword Beam
Clearly inspired by Zelda II: The Adventure of Link, it consists of throwing a projectile when attacking while sneaking; the more hp you have and focus on one target, the more damage you will deal with this ranged attack

The mod also adds weapons already holding specific skills in the wild such as wooden or iron swords in simple vanilla dungeons for examples (like the sticks available in the creative menu).

I would have to share however that some of sword skills might not work nearly as well if not properly taken care of in packs (for example the Parry allows you to disarm an opponent , which can cause issues with many other mods which add creatures which are not meant to be empty-handed, or can look weird if the enemy is just holding a weapon as part of their custom model)
I have not experienced any major performance issue while playing with the mod's latest version, that said due to this mod exploiting vanilla Minecraft's combat as a base, any mod susceptible to tweak the way attack cooldowns work or switch up the combat system entirely will most likely be incompatible with this mod (looking at you Immersive Combat ).
Another note is that aesthetically-speaking there isn't much to talk about, since the moves mostly involve first-person actions without custom animations involved at any part of the process.
(This means I won't really take the Aesthetics into account for the overall rating)

In conclusion

This is a really really nice mod which some flaws which will probably last as the mod seems no longer updated even on Planet Minecraft;
Speaking of planet Minecraft, there's a crazy amount of datapacks on there, even more than on curseforge or modrinth, which means that just looking at those platforms alone will make you miss on some interesting concepts especially in the wide realm of structure enhancements and reworks.
Anyways, it is of note that technically-speaking, dynamic sword skills is an official fork of Zelda Sword Skills , an older 1.7.10 mod by the same author (which has itself a continuation in the same version called Zelda Sword Skills Continuation by the way) which also contains various features and mobs outside of the sole combat system.