This item is too strong against assassins or someone who uses burst in general. I can't tell you how many games I've lost because a DD user gets ahead, then it becomes nearly impossible to kill them unless it's a full on 5v5 fight.
or someone takes a 
to their life steal?
is a great counter item to dd, and yes it should be decreased. Not only can you get that op healing you can get the 
ofc. 
is pretty strong with that build because of his W increasing healing by 20%.
Then 
will be in just as bad a state it was in before the buffs. We need to find a middle ground for it, or else it'll just be obsolete again.
20%
Or maybe 25% and a cost increase
Right now it's at 3500g versus BT's 3700g. Unlike BT it also grants 10% CDR. Same 80 AD.
I get it was targetted more at fighters though so it desired a lower cost. Maybe both BT and DD should be weaker at a lower cost.
I believe BT is super duper expensive atm because I think they originally wanted to crush BT rush "cheese" from the game a few seasons ago and IE used to be more expensive (and Ruined King was more nerfed). IE is less expensive now though and Ruined King is an intermediary.
Can entice ADC to rather want BT more by closing the cost, but lower both costs making room to reduce both in terms of slot efficiency/effectiveness without kicking em to a late game luxury.
30% DD dmg reduction is still probably a bit high however you slice it though
The closer in terms of power and expense BT and DD can be bridged the less getting destroyed DD can be to be ok on ranged overlords. If the costs of both go down too the less overall effectiveness and annoyingness each can be and still retain build diversity
