Battle Engineer

You decide to take arms and join your comrades into the heat of battle. Your machines and magic come to aid you in increasing your combat proficiency. You are quick to improvise in battle, repair your machines quickly, and build small items for your allies during battle. 

Combat Experience (Level 3)

You train your body and try all sorts of weapons to become proficient in combat. You gain an additional proficiency to heavy armor, shields, and martial weapons(with optional rules to firearms as well). You can use your bonus action to attack if you have spent your action to cast a spell. You use your intelligence modifier for your hit roll and damage roll instead of strength or dexterity. You also gain these spells:

1st Level (At Level 3)	Shield, Magic Missile
2nd Level (At Level 5)	Branding Smite, Cloud of Daggers
3rd Level (At Level 9)	Crusader’s Mantle, Blinding Smite
4th Level (At Level 13)	Fire Shield, Resilient Sphere
5th Level (At Level 17)	Steel Wind Strike, Destructive Wave

Extra Attack (Level 5)

Starting at 5th level, you can attack twice, rather than once, whenever you take the Attack action on your turn.

Enhanced Tinkering and Repair (Level 9)

You gain the spell Mending and can cast it with a cast time of an action. You can repair any non magical item or built construct that received minor damage or lost hit points, then you can repair the damage with two actions if you have the tool proficiencies and the material cost required or heal 10 hit points per 30 gold pieces worth of material used to repair a construct. You can also craft any non magical item that costs less than 1 gp within an action only during combat and can be used five times per long rest. 

Magical Precision (Level 15)

You can use your magic to enhance the strike of your next weapon or unarmed attack. When casting a spell of level 1+ or using a spell using your Spell-Storing Item class feature, you gain one stack of Eurika. You can have up to 5 stacks and they reset after a short rest. You can use one stack of Eurika to make your next weapon or unarmed attack to critically strike an enemy only once per turn.