using this just as a jumping off point:
GonadSandStrifE wrote:
It's not all that bad, but from 50-75 it's a little tough to justify, especially when you're an already melee-proficient Elvaan.
at 60 gain souleater (okay. so it's not super strong on redmages, but for the hp strong (elvaan, hume to a lesser extent), you can blow it before convert, knock down some of that 'extra' hp; click off and convert.) and of course, Last Resort and weapon bash (but I'm not aware of any 2handed weapons redmage have good skill in)
as far as traits go: attack bonus I, and II (two at 60 main)
resist Paralyze I, Arcana Killer (probably not super useful)
at 74 gain stun. is this worth more than erase? not sure. is it worth more than the elemental debuffs? not sure. (*this is the HNM reason for a lot of rdm/drk, that and increased hp which = bigger damage on Spirits Within but that's not a valid reason for doing it in EXP)
you will also gain: Absorb-Mind (as a dark magic it's related to int {good for tarus} ) Absorb-Chr, Absorb-vit and Absorb-Agi at levels 62, 66, 70, and 74. might offset some of the utility you would otherwise get from another sub.
the above is mostly just conjecture, since I play neither dark nor redmage, so I'm not sure how effective this would be in practice, I do know that I would not hesitate to invite a rdm/dark if I was in the market for a mage who wasn't going to be main healer (I play whitemage mostly, so this happens alot for me) and especially with elvaan as a race choice, rdm/drk *should* be capable of melee through to 75, while some more 'support-related' builds, may have some issues.
just to provide some more of the things that Dark Knight gives as a subjob (to redmage in particular) since it hasn't really been discussed in detail yet.
Hope this helps!
~Am