Most people are aware that the specialized armor sets give the same damage bonus as non-specialized armor (Skolver, Shadowsun, etc). I have come up with a few ideas to make their specialization become more appealing. I have also included my thoughts on some other armor lines that I think would be helpful.
Chroma Lines
[3*] Chroma- Damage vs Slime Low on each piece.
[4*] Virulisk/Salamander- Damage vs Slime Medium on each piece.
[5*] Deadly Virulisk/ Volcanic Salamander- Damage vs Slime High on each piece.
[5*] Arcane Salamander- Damage vs Beast and Slime Medium on each piece.
Angelic Lines
[3*] Angelic- Damage vs Fiend Low on each piece.
[4*] Seraphic- Damage vs Fiend Medium on each piece.
[5*] Valkyrie - Damage vs Fiend High on each piece.
[5*] Heavenly Iron- Increase the damage vs Fiend to Medium on each piece.
Drake Scale Lines
[3*] Drake Scale- Damage vs Beast Low on each piece.
[4*] Wyvern Scale- Damage vs Beast Medium on each piece.
[4*] Silvermail- Damage vs Undead Medium.
[5*] Dragon Scale- Damage vs Beast High on each piece.
[5*] Radiant Silvermail- Damage vs Undead High.
Gunslinger Line
[5*] Deadshot- Damage vs Undead High on each piece.
Other Ideas I have.
Magic Lines
[5*] Divine- I'm not really sure about how to not make it basically the same as Valkyrie. Add Undead medium on the mantle maybe?
[5*] Grey feather- Fill elemental defense to the max. Add Frost resist.
[5*] Chaos- Change its elemental defense to shadow. (uses shadow materials to craft.)
I apologize if these same ideas have been posted before.
For the Chromalisk lines the 3* can keep accumulative +1 per piece as it is currently but the 4* each have +2, the 5* can have +3 per part to have maximum (+6) family bonus at the highest upgrade rank.
See above for Angelic and Drake lines.
Since Gunslinger lines separate at 5* I can not retort giving the 5* pieces each +3 undead family bonus.
Chaos is supposed to be the Mad Bomber version of the Magic lines, giving up defenses for offensive bonuses. Giving these bonuses to Divine, the set with split shadow-element, would defeat the purpose of variation. Changing Chaos to shadow damage would befit its characteristics, giving it status resistance would be rhetorical with the universal damage and charge bonuses.