Advanced ArcTech Arm

Created by collaboration of wizards and dwarves blacksmiths, This arm attaches itself to the user and can't be removed against users will. Its made from durable aloys and magic infused woods because of that its more powerfull and durable than a regular arm . It also have a arcane power core that enables user to create shield infuse their strikes with arcane power etc. 

Enhanced Strength and Durability. Any checks or attacks made with this arm made with STR score of 20. You can also use your reaction to reduce incoming damage by covering your arm with the energy in it and blocking the hit with this arm. Damage reduces 1d4 for every charge you spend.Can't use againts AoE effects.

Designed for Hazardous Environmet.  The arm resistant to acid,cold,fire damage.

ArcThech Core. Normal ArcTech core draw wild magic in the world. It can't gain charge in an anti-magic field or a place without magic. Item gain 1 charge for every 2 hours and holdu up to 10 charges. Power core can be replaced by a stronger one by a  ArcTech master. DM decides its cost and neccesary materials. It can chage its max charge capacity or charge rate.

ArcTech Circuits. Any attack made by this arm counts as magical. If arm enters an anti-magic field it becomes disabled.If targeted by dispel magic, the user must succeed on a Constitution saving throw against the caster's spell save DC or arm becomes disabled for 1 minute. When disabled user cant use the arm like a paralyzed normal arm. 

Upgrade Slots. Arm designed in modular manner and have 2 upgrade slots. This upgrade slots can be used by doing neccesary modifications. This modifications can be made by only ArcTech masters and upgrade costs are determined by them.

Shield Projector(Upgrade). You can use your bonus action and 1 charge to Project a shield until your next turn. This shield has small sized and gives +2 to AC when its active.You can double charges used to to create bigger and stronger shields. For every doubling you can gain +1 AC and size.(For 2 charges +3 AC and normal size shield ,for 4 charges +4 AC and Full size shield etc.).(Optional: If 8 charge spend like this user cant move and acts as a total cover[like a arcane energy wall].)

ArcTech Converter(Upgrade) You can spend lvl 1 spell slots to gain 2 charges lvl 2 spell slot for 3 charges and 3 lvl spell slots for 5 charges.

Force Blade(Upgrade) You can create a arcane energy blade from your upper wrist as a bonus action. All force blades are finesse .You dont have additional proficiencies for created weapons(If you are not proficent with given weapon type you cant add your proficiency bonus to the attack). You can spend 1 charge to create a force dagger that deals 1d4+STR force damage for 1 min. You can spend 2 charges to create force sword that deals 1d6+STR for 1 min. You can spend 3 charges to create force long sword that deals 1d8 +STR for 1 min. When your force long sword active you can spend 5 charges to expand blade to 10 feet and cleave the area in front of you as a action. You swing your energy blade 90 degree 10ft cone. Targets in the area must take DC 13 (+ proficiency bonus if you have proficiency with long sword or great sword). Targets take 2d6 + STR force damage on failed save and half as much damage on successfull one.

Arcane Focusing Gems(Upgrade). You can focus the arcane energy in the arm trough the gem and fire a arcane beam as an action. You can spend 1 charge to make a ranged attack that deal 1d6 force damage(60 ft range) . You cand spend more charges for aditional 1d4 damage and 10 ft range. İf you spend more then 4 charges roll 1d20 for save. DC is equal to (charges spend - 4) X 5. On failed save you lose all charges and you must make STR save agiants same DC. on fail you knocked prone. If damage kills a creature or destroys a object beam will continue in its trajectory until it reaches its range or cant pass trough.

ArcTech Elemental Infuser(Upgrade). You can work  for 1 hr to change your damage type when you use charges. You can reconfigure your damage type by using charges. You can convert your damage to Fire Lightning Cold and Earth(Bludgeoning damage counts as magical damage).    

 ArcTech Circuit Breakers(Upgrade). When arm targeted by dispel magic you have adventage on Constitution saving throw for resisting it. On failed save arm is disabled 30 sec instead of one 1 min.

ArcTech Energy Reserves(Upgrade). You have 5 more charges. Core will first charge itself then charge up reserves. Reserves will be used after cores charges are exausted.

ArchTech Vampiric Trichomes(Upgrade). You can make a meele attack with this arm as an action. It will deal additional 2d6 necrotic damage to the target. You will gain 1 charge for every 4 necrotic damage dealt by this attack.

 Adamantide Plating(2 Upgrades). You can add adamantide plating in to your arm. Your attacks made with this arm counts as adamantide weapon attack. Also when you use your reaction for blocking damage with this arm you are immune to bludgeoning slasing and piercing damage that isnt from adamantide weapon.

Notes: ArcTech concept is classic magic and technical engineering combined. In this tech logic and energy comes from magic side and actual grabing and lifting punching and durability comes from tech side. This item is a prostetic arm designed for high rank military officers or everyone who can afford it. It can be upgraded with many choices., Needs attunement by a humanoid with a missing arm(Size is up the DM).