Platform:
PC

ISP:
Three

Type of Internet Connection:
Mobile Broadband

Internet Connection Speed:
3G

Date & Time:
All the time

Frequency:
Again, all the time

Character Name:
Sargent

Race:
HumeF

World:
Leviathan

Main Job:
DNC99, Also occured on other jobs in the past

Support Job:
THF49

Area and Coordinates:
Dynamis zones, various coordinates

Party or Solo:
Both, I've done Dyna a lot so can't recall every Party Member.

NPC Name:
None

Monster Name:
All "Replica" type mobs (AKA, "Simulacra" mobs)

Steps:
Basically the above mobs have Physical Damage Taken traits that massively reduce the damage they take from player melee swings and weapon skills. I say PDT since nukes and Elemental Weapon Skills do normal damage. However, all pets ignore this PDT and deal normal damage to these mobs.