Enduring Ideal decks often put enchantments into play, some are auras like Faith's Fetters. these auras come into and have to go on a creature (or artifact or whatever), however, auras only target when they are on the stack. So Faith's Fetters could get put on Simic Skyswallower in this way. On creatures like Progentus, the Protection From ability specifically destroys the aura.
Does the Aura get to enchant the Progenitus at all, if only for a very brief time, or does it never actually come into play? Say, if the only creature in play has pro:red and I use Enduring Ideal to search for Galvanic Arc, do I get to deal 3?
It can't be enchanted, at all, even for a second. Protection covers four things, abbreviated DEBT (Let's say it a creature with pro:red): Prevent all
Damage that would be dealt to the creature by red sources; The creature can't be
Enchanted by red sources; It can't be
Blocked by red creatures, and it can't be
Targetted by red spels or abilities. Enduring Ideal gets around the "T" but it can't circumvent the "E".
From the most recent Riki Rules, referring to Deathrender and Progenitus:
Why does the Deathrender fail to attach itself? This is the inevitable follow-up question. The confusion arises here because players think of protection’s “no targeting” section, which normally prevents the equip ability itself. But without the targeting, they think that it is okay to go ahead and attach it through other means like Deathrender. However, rule 502.7d states “A permanent with protection can’t be equipped by Equipment that have the stated quality…” This is a blanket statement that means that an equipment can never be attached to such a creature. Not even for a second. Deathrender does not attach itself to Progenitus and fall off; it just never gets there.