We just leveled up! I posted some notes about my experience playing this character in my last blog entry.
I continue to be happy with the role play opportunities of the character, and it performs well enough in play so I do not feel like I am penalized by 'bad' choices. Good on you 5e.
In our first outing since gaining third level we encounter a bunch of gnolls in close quarters situation. I through myself in harms way repeatedly to protect the squishy characters, and my AC 19 splint and shield hold up very well, especially when the DM rolls poorly for the monsters. I take minimal damage, and without resorting to dodge. In these encounters with the gnolls we are in small rooms with doorways and not a lot of room to maneuver. The party casters unload lots of literal fire power in the very last encounter: flaming sphere, burning hands, firebolt, sacred flame, channel divinity radiance of the dawn. I somehow manage not to get caught in the flaming sphere and burning hands, so my fire resistance continues untested! Not that I am complaining however.
Also speaking of fire, the tiefling racial ability at third level is Hellish Rebuke. Technically, this requires a free hand to cast which makes it not very useful for a sword and board paladin. In the spirit of rulings not rules, we discussed this. Though it has a somatic component, the spell description basically says you point at the bad guy who hurt you and utter the words. From a color perspective, I make those words be in infernal. So basically we discussed what would it hurt if my character could use a sword hand to point a finger at the enemy, would that really break anything? We decided not to change the spell per se, but to say tieflings, or at least this tiefling had a little more flexibility with this racial spell as a somatic component. I am happy to abide by the letter of the law, if I cannot use the hand at all - such as restrained or carrying a heavy load or something like that, I could not use the spell. Rulings let me keep a cool ability which has perfect color for my character.
As to spell casting, I get another slot and a my oath spells which are always prepared. I am not sure if I will ever choose Bane of one of the other choices, and I am on the fence whether Hunter's Mark will turn out to to be useful. It may see use in situations where I can drop minions with a little extra damage beyond what I normally can do with my weapon. I will have to test it. For now, Divine Smites continue to use most of the spell slots but the additional choices are nice to have.
I did not get to use my main oath ability - Vow of Enmity. I was about to use it on the gnoll I had just Hellish Rebuked, when it ran from the room and time ran out. See if I can get him next session!
The dice never lie.