Krexel equips?

I heard the ESG boss in the Golden Temple drops basically a better version of a zhelm. Any details?

Not better. It has similar stats to helms 2 and 3. I'll see if I can dig them up but no promises...
Ah, here. It comes in three varieties:

Level 50
30 HP
30 MP
45 def
45 Mdef
5 ACC
5 AVoid
8 slots

Level 70
40 HP
40 MP
60 def
60 Mdef
5 INT
5 STR
5 DEX
5 LUK
8 slots

Level 90
60 HP
60 MP
60 def
60 Mdef
5 INT
5 STR
5 DEX
5 LUK
10 ACC
10 Avoid
2 speed
1 Jump
9 slots

You can see how it's similar to the weaker zakum helmets. Actually the stats are very similar to the Pirate hat which came out at about the same time.

The guitar boss drops a level 30 pink guitar-shaped pendant that just adds 30 Mdef and 30 def, so it's not too great. He also drops that Taipei 101-shaped sword but that's tradeable so I'm not counting it. Here's what the pendant looks like, if anyone cares what pendants look like: