Why is Elemental defense so popular for FSC? As far as I can see the only thing in there that does elemental damage is the red rovers, which seem very easily avoidable. It seems like normal is the most important, with shadow being a distant second, (sure zombies are easy to avoid, but so is everything really, they're so common that you might as well have defense against them if you get cornered somehow right?). Currently picking gear, thinking I'll go with the magic cloak and hood series since they are the only reasonable thing that gives fire resist at 4*, but still, when considering 5* armor, why does everyone rave about elemental defense?
Why Elemental Defense
But the damage from fire is only reduced by fire resistance, not elemental defense. The only status which actually does elemental damage is shock.
edit: (fire damage MAY be reduced by normal defense as well, but I'm not sure there, I think the damage counts as normal damage, you can notice this as well when you inflict statuses on mobs, fire always ticks blue numbers, shock will tick in accordance with the mob's elemental resistance/vulnerability.)
http://wiki.spiralknights.com/Damage#Elemental_Damage
"Damage dealt by attacks imbued with the fire, shock, or freeze status conditions contain elemental damage"
http://wiki.spiralknights.com/Slag_Walker#Slag_Walker
All of the Slag walker's attacks have either fire+shadow, or fire by itself, so having elemental resistance is probably a good idea.
The initial dmg of the fire atks are half elem half normal, but the fire DoT ticks are normal iirc.
The reason elemental is recommended in FSC is because walking into magma results in a hefty portion of elemental damage. Likewise, Vanadork's mask phases are full of elemental bolts (I think his fire balls are also at least partially elemental). Shadow defense is nice, but not too necessary because slag walkers are slow and stupid. With the exception of the last room in d27, they are easily avoidable or otherwise dodge-able. It's the other reason Grey Owlite is a favorite- even though it confers no particular benefits inside FSC (other than tanking Red Rovers), it makes shielding bolts during the mask phases easier. But if you're skilled, even that is mostly moot- there are people who run FSC/Vanadork with a Swiftstrike.
the breath from zombies is fire and there is fire everywhere. that's why.