The question brought up often about this set is how it compares Netherwind? Item for item Enigma is much better. As for set vs set...

Well it all depends on how you fill out your other slots. Netherwind's 8 piece bonus is generally considered an 6 percent increase in damage.

The bonuses on Enigma aren't that incredible. The five piece bonus is generally only useful for lvl 63+ and depends on how much hit you currently have. Although this set also has a lot of stam. Which is valuable for encounters like Ouro.

In the end I look at Enigma not as a set. But a series of items to flesh out gaps in a set of gear to achieve high damage, crit, hit and some penetration.

Well yeh if you look the spells it says :
Enigma's Answer
Instant
Increases spell hit rating by 40 for 20 sec. Stacks up to 4 times.

do i get these items back for free when i destroy them like the aq20 pendant and the zul gurub pieces?

For mages seeking out this set for looks and can't find a matching belt, you may want to snag the https://vanillawowdb.com/?item=21582 Grasp of the Old God from C'Thun. The color scheme is identical and it bears the same logo as the robes. The https://vanillawowdb.com/?item=21619 Gloves of the Messiah go nicely with the set as well, though they suit the priest set somewhat better.

The tooltip is inaccurate about the 5-piece bonus (see https://vanillawowdb.com/?spell=26129"">(Spell #26129) ): it only grats +40 hit <i>rating</i>. Sorry, that 60 you're bringing out of retirement won't be able to hit Cataclysm mobs just yet.

Here are the total materials required to complete every piece of this set.

x1 - https://vanillawowdb.com/?item=20933"">(Item #20933) drops off https://vanillawowdb.com/?npc=15727"">(NPC #15727) (88%)
x1 - https://vanillawowdb.com/?item=20926"">(Item #20926) drops off https://vanillawowdb.com/?npc=15275"">(NPC #15275) (78%)
x2 - https://vanillawowdb.com/?item=20932"">(Item #20932) drops off https://vanillawowdb.com/?npc=15509"">(NPC #15509) (97%)
x1 - https://vanillawowdb.com/?item=20927"">(Item #20927) drops off https://vanillawowdb.com/?npc=15517"">(NPC #15517) (100%)

Idols are obtained from chests placed in various locations throughout the instance.
x2 - https://vanillawowdb.com/?item=20877"">(Item #20877)
x2 - https://vanillawowdb.com/?item=20876"">(Item #20876)
x2 - https://vanillawowdb.com/?item=20875"">(Item #20875)
x4 - https://vanillawowdb.com/?item=20874"">(Item #20874)

Scarabs drop off trash mobs, and can also be obtained from chests.

x5 - https://vanillawowdb.com/?item=20862"">(Item #20862)
x5 - https://vanillawowdb.com/?item=20859"">(Item #20859)
x10 - https://vanillawowdb.com/?item=20860"">(Item #20860)
x10 - https://vanillawowdb.com/?item=20861"">(Item #20861)
x5 - https://vanillawowdb.com/?item=20865"">(Item #20865)
x5 - https://vanillawowdb.com/?item=20864"">(Item #20864)
x5 - https://vanillawowdb.com/?item=20858"">(Item #20858)
x5 - https://vanillawowdb.com/?item=20863"">(Item #20863)