Debuffs (and buffs) - which ones stack, do they extend?

"Screerider;c-1230337" wrote:
Tarkin's potency is supposed to stack, but I only see one buff.

Because the visible buff comes from his special ability, "Intimidation Tactics"" which expires after 3 turns, whereas his primary omega skill is a passive buff that stacks invisibly.

Generally, "special" damaging debufs (shock, burn) don't stack, but "generic" ones (DoTs, Expose) do. Almost with out exception, status modifiers don't stack (defense down, speed down etc)