A large portion of relevant modules/templates have now been switched to cargo. Various usages of SMW throughout the wiki need to be replaced by the new functions, in particular item tables. If some pages do not show up but contain no errors, please null-edit them. To see how you can help with the port check out Path_of_Exile_Wiki:To-do_list/SMW_migration (and leave a comment on the talk page if you have questions).
Unflinching is a Notable Ascendancy passive skill for the Juggernaut that grants an additional maximum endurance charge, a chance to gain an endurance charge when hit, and generates an endurance charge every second if you were hit in the past 4 seconds. Additionally, whenever you gain an endurance charge, there is a chance it sets your number of endurance charges to its maximum.