The EK's magic is kinda trash though.
This is attempting to layer one of the top 3 strongest classes in 5e on top of the fighter.
It's gonna be overpowered as nine hells or require stripping out all the parts that make it feel like a paladin.
I'm pretty sure that we disagree on what makes it 'feel like a paladin.'
But as a super quick mock up of Paladin subclass for the fighter:
Level 3: Divine Smite (this is toned down as they have less spells, could be easily toned down more by decreasing the damage die.) + Channel Divinity (different ones to choose from)
Level 7: Aura of Protection (You could make this so that there are several auras to choose from. Like you could pick Aura of Warding or Devotion instead.)
Level 10: Aura of Courage
Level 15: Improved Divine Smite (this is a bit boring and possibly OP. There could be couple of oath abilities to choose from here instead.)
Level 18: Cleansing Touch. (THis is decent. But we again could have oath abilities to choose from instead.)
1/3 spellcaster with (perhaps limited) access to cleric spells. Casts with wis because that's how divine magic should work and judgemental arses do not need to be likeable.
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Something like that should work. This of course was from the top of my head written in three minutes, so it probably has issues but you get the general idea. I'd build it like the totem barbarian, so that instead of having just one feature per level that gives features, you get to choose from several. That way you can build more reflect different oaths.