The Harrowing - How does it work?

So, I have yet to have the opportunity to cast this spell or have it cast against me. From the wording, it's hard for me to tell exactly what will happen.

If fewer than 6 things have died on your side, does it only summon that number of things, or do some of them get summoned twice, to make 6 copies? (Example - only 3 of your allies have died, you cast Harrowing - do only those 3 come back, or do 2 copies of each come back to make a total of 6?)

Thanks for the answer!

Essentially:

1. Create a list of all allied units that have died so far this game and order them strongest -> weakest
2. If you have an open slot on your board, summon a copy of the next unit from that list and give it ephemeral
3. Repeat #2 until either your board is full or the list is empty

Some interesting points:

• All summon and last whisper effects proc.  This makes The Rekindler especially valuable, as he will create a non-ephemeral copy of your strongest champion so long as he is summoned in slot #5 or less (if he's in #6, he will try to create the copy but you won't have a free board space so that copy will evaporate)
• The copies from The Harrowing add to your rez pool--e.g., even if you have only played one "authentic" Hecarim, Harrowing #1 will copy that, Harrowing #2 will copy both = 2 total, and #3 will produce 1 + 1 + 2 = 4 total.
• When considering how "strong" something is, Harrowing will take into consideration champion L2 stats (assuming they leveled) but not any buffs that only apply when the unit reaches the board (e.g., They Who Endure is only ranked by its 1/1 stats).  I'm honestly unsure whether "everywhere" buffs like Poro Snax and Mistwraith are taken into consideration.
• Harrowing only gets value from things that have died, which can create some interesting dynamics.  For example: yesterday I was playing a game where I intentionally did a bad block so that my The Rekindler would die and I would resummon him + an additional champ when I played harrowing the next turn.
• Harrowing's value is also limited by the number of board spaces, so if you plan to play it next turn its a good idea to try to kill off all your less valuable units this turn to free up space.

Kind of a necro but just wanted to add:

Harrowing and Kalista (they work the same way afaik) WILL choose They Who Endure based on current stats as I play both T.W.E and Harrowing in my Hecarim/Kalista rush aggro deck.  Upgraded Kalista chooses T.W.E over Rekindler and Darkwater Scourge so it must be that way.