Fun Fact:
Current PTR patch Duplicates can kill T16 rift guardian (full gear, gems, paragon of course). Use Flame Blades build and switch Spell Steal for Duplicates. Switch Elemental Exposure for Illusionist. Next test: GR100 solo, with no main stat from paragon, no augments, and only 2 non-ancient items equipped.
GR100 done in about 10.5 mins sloppy and they slaughter the RG.
Next test: GR110 solo, +1076 paragon main stat, no augs, only 2 non-ancients.
GR110 is noticeably slower but still effective enough. The duplicates can still kill elites and the RG. It took 8 mins 13 seconds because I had lots of elites that kite. When encountering elites I ignite them, cast blades away from them, tele. next to them, pop duplicates and stop casting for 5 to 8 seconds. Most times my EB is missing the elites because they would kite away.
I think the duplicates inherit the FB 2p on death effect because there were lots of fire meteors dropping on top of the elites and I had to re pop the duplicates multiple times.