hell yeah

Sorry. It was admittedly not a great idea on my part to assume everyone uses Recipe Browser, so I've added a pastebin link with all the recipes (to avoid cluttering the description).

wheres the list of the recipes so i know how to make them

Well... I won't promise anything. I'm not really that much of a programmer. Adding some recipes was not too hard, but I don't know if I can do an NPC.

And if I do succeed, don't expect the items to be cheap. As a long-time player of this game, making mods that removes all challenge is just not in my interests. If what you want is an effortless way to get them, I suggest installing Cheat Sheet or Hero's Mod.

I mean the vanities, not the wings or weapons. you could just make them a recolour of the guide or something and then maybe after plantera has been defeated they start selling wings/weapons

Pretty subjective statement. To me, that would make it too easy to get them. If you want to circumvent earning them the vanilla way, then there should at least be something there to compensate for it.

I also didn't feel like designing, spriting, animating and programming an entire NPC just to get the armors.

would be better if it just added an npc that sold them

And thank you for the kind word :)

thx you for this mod

20 Cobalt Bars, 15 Souls of Light and 5 Diamonds at a Mythril/Orichalcum Anvil.

I'd recommend installing the Recipe Browser mod so that you can find recipes for modded items easily in the future.

how craft the arkhalis sword??

This mod is mainly meant to be a way to acquire items only available through endless grinding of hardmode bosses, or in other words: the stuff you get out of treasure bags. Like planetdean said,
in 1.3 the Arkhalis works differently than in 1.4, and is not found in a treasure bag, so it's not craftable there. In 1.4 it's found in treasure bags, has had it's stats buffed and have acquired a defense-bypassing property, so a Mythril Anvil is more than fair.

As Arkhalis isn't a treasure bag exclusive in 1.3, adding it to my mod makes no sense to me. Normally I'd just recommend imkSushi's mod or Fargo's Mutants to you to make it craftable, but since there doesn't seem to be a standalone mod dedicated to making Arkhalis craftable, I've gone ahead and taken the extra effort by creating "Craftable Arkhalis" for tModLoader 1.3. The recipe isn't so lenient as to let you have it from day 1 of a playthrough, but it does use 100% Pre-HM stuff to make it. I hope this will do as a workaround :)

The Arkhalis is obtainable like that in the 1.3 update, however in the 1.4 update it was moved to hardmode and became a dev item while the Terragrim took its place in pre-hardmode.

Arkhalis is obtainable before hardmode in the Tmod loader version of terraria, with a 10% of being obtained from enchanted swords

Ta bien

Arkhalis is a hardmode item unless you are playing on the 10 year anniversary seed. If there is a way for tModLoader to check for if you are playing on a special seed, I'd love to make it so that you only need a base level anvil within those worlds, but otherwise I don't see a reason to base the recipe on the exception instead of the rule.

Arkhalis shouldn't need orichalcum/mythril it's obtainable since prehardmode