Advanced systems: Unique attacks and crafting (under construction)

So, as of now I'm currently adding a few things to the system that is of a more advanced nature. Among these are a few more advanced non-magical attacks, as well as creating crafting systems.

First off, we're going to go into Unique attacks.
So, what is a unique attack? Simply put, it's a weapon technique that relies on specific statistics, weapon types, etc. that can be learned through getting a "perk" with that name.
So far, I have three different ones, but more will be added as inspiration and/or suggestions are granted to me.

Iai - Katana technique. Requires 18 str to get. In order to use the Iai, the katana needs to be sheathed. The user must then pass a 5d6 str check, after which the opponent will be allowed to dodge or block as normal. The attack will then deal (base weapon damage + 1d6*dex modifier) in damage. If the Iai crits, the base weapon damage will be doubled, not the bonus damage.

Butterfly cut - sabre technique. Requires 18 dex to get. The user must perform 1 successful 4d6 str check, one 4d6 dex check, and one 4d6 perception (int or dex, whichever is higher) check. If all three are a success, the recipient of the attack must succeed 3 5d6 block/dodge checks.
If any of the attack rolls fail, the butterfly cut fails. If the attack rolls succeed, and any of the blocks fail, the recipient takes 3 attacks, each with DR applied normally, and they deal base weapon damage.

Backstab - Dagger technique. Requires 15 dex. All attacks performed with daggers from behind automaticly deal critical damage.


Proffessions/crafting
So, as of now I have added a few different crafting types that are avalible to players.
These are: Artificing, Herbalism, Alchemy, Engineering, Repair, Enchantment.

Artificing: combination of magic and science. Artificers combine the power of magic with more normal crafts in order to create magicly powered artifacts. Can be combined with Engineering in order to create things such as mana-powered killer bots, rayguns, etc.

Herbalism: Knowledge of nature and the herbs within, can be used to find natural cures in the wilderness, and may be combined with alchemy.

Alchemy: Creation of potions, poisons, chemical bombs, and more. Usually deals with concentrating the effects of plants and magical reagents to greater effects, creating healing potions and more.

Engineering: Creation of Guns, ammonition, and at very high levels, Vehicles, etc. Requires materials such as gunpowder, metals, wood, etc.

Repair: Fixing damaged items such as armors, swords, clothes, and more. Requires materials akin to what the object to be fixed is made out of, as well as tools of the trade. This can be anything from needles and tread to a anvil and forge.

Enchantment: Application of magical effects on weapons and armor. Can be used to enhance previously average weapons to perpetually burn, chill everything struck to the bone, or slice through armor with ease. And in return, can make armors absorb fire, ice, and even the raw power of magic itself.

I will go on to define specific skills within these different crafts when I have time and inspiration. But for now I will define perks.