This title has to be likeā¦ completely undo-able unless your using the Marquis hack right?
āIn Incursion, Destroy a sentry without taking damage, 25 timesā I mean god damnā¦ i cant think of how else to do it >.<
Oscar in the side tunnel with the turret is hard, but plausible.
Or, just do it fair?
You know: Ace their team and destory their turrets?
But no damage what so ever? Not one stray bullet from a opponent come on now that HAS to be up there as almost impossible. But even Marquis isnt a guarantee. all it takes is an opponent marquis to hit you and done. Or is the achievement no damage from PvE things (Turrets, minions, sentry )
When all said and done itās gotta be the hardest in game to do
I tihnk it means āno damage from the turretā or maybe āno health or shields missingā Idunno, Iām about 5in and Iāve like, only played Whiskey in PvP.
I applaud your accidental achievement progress sir! 
It would be nice if it was a bit clearer. Hope you get it soon!