Here's a homebrew I have that attempts to combine Fighter and Artificer in sort of the same way that Eldritch Knight combines Fighter and Wizard. Please take a look and tell me what you think.
Bonus Proficiencies 3rd-Level Gadgeteer feature
You gain proficiency with a set of Artisan's Tools of your choice.
Infuse Item 3rd-Level Gadgeteer feature
At 3rd level, you gain the ability to imbue mundane items with certain magical infusions. The magic items you create with this feature are effectively prototypes of permanent items.
Infusions Known
When you gain this feature, pick two artificer infusions to learn, choosing from the Artificer list or the section at the end of this subclass’ description. You learn additional infusions of your choice when you reach certain levels in this subclass. Whenever you gain a level in this subclass, you can replace one of the infusions you learned with a new one.
Infusing an Item
Whenever you finish a long rest, you can touch a non-magical object and imbue it with one of your artificer infusions, turning it into a magic item. An infusion may work on only certain kinds of objects, as specified in the infusion’s description. If the item requires attunement, you can attune yourself to it the instant you infuse the item.
Your infusion remains in an item indefinitely, but when you die, the infusion vanishes. The infusion also vanishes if you give up your knowledge of the infusion for another one.
You can infuse one nonmagical object at the end of a long rest; you gain more infusions known and infused items as you level up in this subclass. You must touch each of the objects, and each of your infusions can be in only one object at a time. Moreover, no object can bear more than one of your infusions at a time. If you try to exceed your maximum number of infusions, the oldest infusion immediately ends, and then the new infusion applies.
If an infusion ends on an item that contains other things, like a bag of holding, its contents harmlessly appear in and around its space.
If you have multiple sources of Infusions, e.g. multi-classing with Artificer, they do not stack and you can only benefit from one of these features.
At 3rd Level, you learn two infusions, and can infuse one item at a time.
Tinker's Shield 3rd-Level Gadgeteer feature
At 3rd Level, when you complete a short or long rest you gain a number of temporary hit points equal to 5 times the number of items you are currently attuned to.
Artifice's Alacrity 7th-Level Gadgeteer feature
At 7th Level, you gain a bonus to your initiative equal to the number of items you are currently attuned to. Also, you learn an additional infusion and can infuse two items at once.
Combat Artifice 10th-Level Gadgeteer feature
At 10th Level, when you use your action to use a magic item, you can make one weapon attack as a bonus action. Also, you learn one more infusion.
At 15th Level, you can attune up to four items at once. You also learn an additional infusion and can infuse three items at once.
Combat Ready 18th-Level Gadgeteer feature
At 18th Level, when you roll initiative, choose one item on your person that has no charges remaining. The chosen item regains one charge. You also learn one more infusion.
I like it, it’s pretty good. I would however suggest bumping Combat Artifice to 2 attacks at 18th level. (That’s one of the improvements I think the Eldritch Knight needs too to be honest with you.)
Here's a homebrew I have that attempts to combine Fighter and Artificer in sort of the same way that Eldritch Knight combines Fighter and Wizard. Please take a look and tell me what you think.
Bonus Proficiencies
3rd-Level Gadgeteer feature
You gain proficiency with a set of Artisan's Tools of your choice.
Infuse Item
3rd-Level Gadgeteer feature
At 3rd level, you gain the ability to imbue mundane items with certain magical infusions. The magic items you create with this feature are effectively prototypes of permanent items.
Infusions Known
When you gain this feature, pick two artificer infusions to learn, choosing from the Artificer list or the section at the end of this subclass’ description. You learn additional infusions of your choice when you reach certain levels in this subclass. Whenever you gain a level in this subclass, you can replace one of the infusions you learned with a new one.
Infusing an Item
Whenever you finish a long rest, you can touch a non-magical object and imbue it with one of your artificer infusions, turning it into a magic item. An infusion may work on only certain kinds of objects, as specified in the infusion’s description. If the item requires attunement, you can attune yourself to it the instant you infuse the item.
Your infusion remains in an item indefinitely, but when you die, the infusion vanishes. The infusion also vanishes if you give up your knowledge of the infusion for another one.
You can infuse one nonmagical object at the end of a long rest; you gain more infusions known and infused items as you level up in this subclass. You must touch each of the objects, and each of your infusions can be in only one object at a time. Moreover, no object can bear more than one of your infusions at a time. If you try to exceed your maximum number of infusions, the oldest infusion immediately ends, and then the new infusion applies.
If an infusion ends on an item that contains other things, like a bag of holding, its contents harmlessly appear in and around its space.
If you have multiple sources of Infusions, e.g. multi-classing with Artificer, they do not stack and you can only benefit from one of these features.
At 3rd Level, you learn two infusions, and can infuse one item at a time.
Tinker's Shield
3rd-Level Gadgeteer feature
At 3rd Level, when you complete a short or long rest you gain a number of temporary hit points equal to 5 times the number of items you are currently attuned to.
Artifice's Alacrity
7th-Level Gadgeteer feature
At 7th Level, you gain a bonus to your initiative equal to the number of items you are currently attuned to. Also, you learn an additional infusion and can infuse two items at once.
Combat Artifice
10th-Level Gadgeteer feature
At 10th Level, when you use your action to use a magic item, you can make one weapon attack as a bonus action. Also, you learn one more infusion.
Magic Item Journeyman
15th-Level Gadgeteer feature
At 15th Level, you can attune up to four items at once. You also learn an additional infusion and can infuse three items at once.
Combat Ready
18th-Level Gadgeteer feature
At 18th Level, when you roll initiative, choose one item on your person that has no charges remaining. The chosen item regains one charge. You also learn one more infusion.
I like it, it’s pretty good. I would however suggest bumping Combat Artifice to 2 attacks at 18th level. (That’s one of the improvements I think the Eldritch Knight needs too to be honest with you.)
Creating Epic Boons on DDB
DDB Buyers' Guide
Hardcovers, DDB & You
Content Troubleshooting