*No Respect* "Down an enemy with a gadget while looking away from them"
The best mode to get this achievement on is Strikeout
The best 2 Rouges to get this with is with Saint or Ronin followed by Anvil and Talon and than anyone else
Saint has trip mines with at max upgrade he can carry two. Trip mines are pretty much claymore mines
Ronin has her Ballistic Knife ability which is an explosive knife when attach to a surface and explodes when an gets enemy near it
Anvil and Talon have c4 which can be remotely detonated. ( this is either base on luck or if your team let you know someone on your c4.)
the other grenades are lot more harder to down someone with out looking.
in the game mode Strikeout your items you set with Saint, Ronin, Talon and Anvil don't disappear on death so you can have multiple out each time you respawn. try to place these items around corners near the target zones.
FYI Ronin Ability counts as a gadgets. if an enemy blows up your gadgets and down their self it still counts.