Originally Posted by
DeadmanWalking
You teleport behind them, and most importantly you teleport somewhere that your big red glowing baboon's ass won't be obviously seen, ace a widowmaker or hanzo, then ult behind them. At that point you will wipe out their squishies, if the tank is still killing you then 1. You did your job even if you died, and 2. Your team should be killing that tank and possibly saving your ass. 3. Consider doing your blossom and then hitting shift to wraith walk away unharmed.
Most likely your lack of success is because you are not using all of the reapers utilities. Reaper is like Batman, you need to use the entire utility belt if you want to be successful, not just throwing baterangs.