The index blaster archon revisited.

If I take a blaster archon from the index, does he lose the reroll aura?

No, you use everything new including costs and profiles but you get the blaster option (and have to replace equipement as specified in the index).

No. You just take the war gear choice. You take everything from the Codex. Just the option to take the blaster from the index.

Good to know.

Now imagine for a second you had a Winged Archon entry in the index that didn't make it to the codex, if you wanted to use him he would still have the leadership aura because you are using his profile and cost that only exists in the index.