I'd like to speak on behalf of the barb mercenary. I'm playing the ragnar barb summon for chuck challenge. The rules are pretty strict about most things so I've only used the barb merc so far. My merc currently has
Urada
,
Erawan
Erawan
Body Armors
'LemKoCham'
Runeword Level: 83
15% Combat Speeds
5% Chance of Crushing Blow
+(144 to 171)% Enhanced Defense
(27 to 30)% to Strength
(27 to 30)% to Vitality
Physical Resist (13 to 15)%
(15 to 20)% Bonus to Defense
,
Kali
Kali
Gloves
'LumKo'
Runeword Level: 48
15% Chance to cast level 13 Seal of Fire on Kill
+2 to All Skills
+15% to Summoned Minion Resistances
-214 Defense
5% to Strength
Maximum Fire Resist +4%
Fire Resist +25%
,
Fawkes
Fawkes
Barbarian Helms
'PulRhal'
Runeword Level: 100
20% Chance to cast level 40 Ember Spirit on Melee Attack
+(2 to 3) to All Skills
50% Cast Speed
1% to Fire Spell Damage (Based on Character Level)
+(26 to 32) to Powder Keg
+150 to Energy
(5 to 10)% to Energy
Fire Resist +30%
+(61 to 90) Life after each Kill
,
Deadfall
Deadfall
Heavy Belt (4)
Defense: (135 - 159) to (178 - 210)
Required Level: 7
Required Strength: 36
Item Level: 19
2% Chance to cast level 2 Shower of Rocks on Kill
1% Chance of Crushing Blow
+(24 to 46)% Enhanced Defense
+(16 to 25) to Strength
Lightning Resist +(11 to 15)%
Socketed (1)
Defense: (485 - 551) to (616 - 700)
Required Level: 24
Required Strength: 62
Item Level: 36
2% Chance to cast level 4 Shower of Rocks on Kill
2% Chance of Crushing Blow
+(69 to 92)% Enhanced Defense
+(36 to 45) to Strength
Lightning Resist +(21 to 25)%
Socketed (2)
Defense: (1270 - 1400) to (1595 - 1758)
Required Level: 41
Required Strength: 218
Item Level: 51
2% Chance to cast level 8 Shower of Rocks on Kill
3% Chance of Crushing Blow
+(115 to 137)% Enhanced Defense
+(56 to 65) to Strength
Lightning Resist +(31 to 35)%
Socketed (2)
Defense: (1918 - 2095) to (2403 - 2626)
Required Level: 50
Required Strength: 436
Item Level: 85
2% Chance to cast level 12 Shower of Rocks on Kill
4% Chance of Crushing Blow
+(138 to 160)% Enhanced Defense
+(66 to 75) to Strength
Lightning Resist +(36 to 40)%
Socketed (2)
, random rare boots and a rare amulet with banish. I didn't prep the runewords before making them and they are all 1 socket. I did add about 30% in skeleton orbs though. The gear is cheap. Necrobots from urada are nice meat shields, the spell dmg from Fawkes boosts the elemental proc on the helm and fire splash on gloves. Deadfall cause shower of rocks. The skills the merc uses are all useful. Gift of the Wild is dmg for the whole party, shower of rocks is a great de-buff for bosses and he uses it regularly. Thunder slam is additional full screen stuns in-between thundergod proccing and Ancient's Hand is good for asshole phys immunes, like necrobots. Again I was sloppy when gearing the merc and haven't tried the other ones but this one has been a great value the party cause hes constantly all over the screen, soaking up damage and causing mayhem. I should probably mention that I'm using wolf stance though, cause its not bear.
About the runemaster discussion above, I'd like to try it because I die a lot if I don't have merc around. But the loss of minion life/damage/other stats seems like it would be significant loss when switching from jewels to runes.