What does the "Flight of Fire" node in the Infernal Shade tree do?

The “Flight of Fire” node in the Acolyte’s Infernal Shade tree reads: “You can cast an additional Infernal Shade or Dread Shade”. By default, there can only be one Infernal Shade on an enemy, so I’m assuming that this node allows you to place two Shades onto the same enemy. Is this correct? The wording is just not very clear as to what the node actually does.

You can cast a second one no idea if you can stack them.

infernal shade and dread shade combined can only have 4 shades total.

if you have 4 dread shades on your minion and cast infernal shade on an enemy 1 of your minions will lose dread shade.
The node makes it so you can make combinations of these 2 skills up to 5 shades rather than 4.

Oh this makes sense. I forgot about that part of the Shade. Thank you