It's a shame that this item can't be enabled on Summoner's Rift because otherwise top lane would become a "who rushes LVDP first wins". Especially because this item would have a lot of potential otherwise.
LadyRenly1 votesit's twisted treeline so the balance is different and not as much priority is on it, for example TT already has Moonflair Spellblade, I dont think such an item could ever exist on SR, so I am sure it will be fine
KONO RUBICK DA1 votesrushing BC on darius would still be the best.
YumaS2Astral1 votes[{quoted}](name=Rubick x Sona,realm=EUW,application-id=3ErqAdtq,discussion-id=eXXNIJUe,comment-id=0001,timestamp=2016-06-29T00:17:48.411+0000)
rushing BC on darius would still be the best.
Not if you were against something like 
for example
Although again, she could build this item herself.
KONO RUBICK DA1 votesit would give a small amount of armor pene in early game unlike black cleaver, gives armor but not hp missing hp heal on darius Q remember? gives 10% cdr instead of 20%, doesn't have rage's passive and has the same amount of AD.
YumaS2Astral1 votes[{quoted}](name=Rubick x Sona,realm=EUW,application-id=3ErqAdtq,discussion-id=eXXNIJUe,comment-id=000100000000,timestamp=2016-06-29T00:21:49.989+0000)
it would give a small amount of armor pene in early game unlike black cleaver, gives armor but not hp missing hp heal on darius Q remember? gives 10% cdr instead of 20%, doesn't have rage's passive and has the same amount of AD.
The armor would be a boon against AD champions, however, protecting from their damage and allowing Darius to better trade with them. You could build Black Cleaver if you were snowballing but LVDP would be the safe option most of time.
It is the same reason why as Zed, you build Maw of Malmortius against LeBlanc and most other AP champions, instead of something like Youmuu's Ghostblade, which would technically benefit Zed more early, but is a risky option.