What about creating an ACTUAL Dark Knight?

[MaraD_]

Nope. I've played FF IV a LOT and Cecil doesn't do this. He casts some damaging spells (Fire - For example) but that's it.

He uses "Black Magic" hence Dark. When he becomes a Paladin he uses "White Magic" that's all it is.

Darkness takes up HP, to deal damage.
I cant remember if it was called that, or Soul Eater in the SNES version.
EDIT: SNES version was "Dark Wave" (and no, he didnt have black magic. Only in the NES version of FF3 did Magic Knights have Black magic (and white magic) which was replaced with soul eater in the DS versions.

If i remember correctly, one of the SNES versions was glitched, so it doesnt eat his HP. most likely the US version. This may be why you dont know about it, since you may have only played the US SNES version. (The original JP version took HP. Plus the US team felt the need to tamper with a lot of stuff, like removing Rosas Pray ability, boss mechanics, etc)
The remakes fixed this glitch. (maybe intentional by the US team)
EDIT: seems i was beaten to the punch by the others lol

option 1 to 3 kills scholar bubble
ask for an adjustment to tenacity to make it a viable stats so we can stack survival instead of dps

Currently a SCH/AST bubble gets eaten before TBN does.
So its currently possible to reorder the priorities to eat HP before temp HP, based on the games current programming.

As for tenacity, it does need a slight buff, but not too much, it still needs to be less than the other options.
It would be possible to "balance it" based on a tank buff that raises their own Tenacity by a %.
As a replacement to some other forms of mitigation. It would end up being used like Vengeance, as an offensive skill, but can still double as a defensive skill.
Make it an ability unique to one job, and it helps bring some variance in the jobs materia options.