How do you build Librarian for CO-OP?

[RogueBanshee]

I have played as the other classes, have not yet tried the Librarian. Was looking for a build suggestion so I do not waste renown points?

[Happy]

Can't say for everyone, but I went with +20 armour bonus, +30 hit point perk, Sword & Stormbolter mk 2 combo with cooldown to shockwave or Lightning.

[Porg Life]

I would take the power axe for better cooldowns than the sword.
20% cooldown on shockwave because it can even stagger broodlords so its a good idea to always have it at hand even if you cant cheese them like with a plasma cannon.

The rest the usual more health, acid protection, but some speed could also work well after a shockwave

[Brother Læknishendr]

Armor: 20% spontaneous combustion, 50% acid damage reduction and 20% armor bonus

Weapons: Axe; with speedboost; combined with battle psyker perk for more melee dmg, or negate dmg-loss due to speed boost. why sacrifce dmg over speed(?), because the stagger the axe, or melee in genereal does, help keeping tyranids off you = less dmg taken.

Mk2 bolter; fire dmg, reliability module, extended magazine and whatever opticals you are comfortable with.

Perk(s): Battle psyker, warp disrupitons or resilience if you feel your armor`s going orange/red all the time.

If you go for a lightning claw build/melee only then the same as above but 20% armor and 30%HP perk seems most optimal.

Edit:

Ligningclaws are best with speedboost too, same reasoning as mentioned above; stagger effect

[Herald536]

Storm Bolter, Force Axe(+Speed Boost), +30% Health PERK, +20% Armour, -20% Lightening. (Reduces cooldown to 0.5 seconds, VERY devastating).

[Silverquick]

Even though I normally play Chaplain,

I have to admit this is my second favorite. Librarian is surprisingly tough, but not in the way you'd think. I use Force Sword instead of Axe, and the Speed Boost on the Sword, and you can literally keep an entire pack of enemies staggered.

I've Clutched with Librarian so many times in Multiplayer because you can face down an entire pack by yourself with just Bolter and Sword.

Mow them down with Bolter until they get close enough.
Slash repeatedly keeping them staggered
Lightning into them when they're close.
Slash with Sword/Axe 4 times
AoE knockback and Bolter a few more down
Slash with Sword/Axe again when they close
Spontaneous Combustion (the Fireball when there's too many and it wipes them out)

Its just this repeated Shock, Slashing, Chain iLightning, and Bolter fire. Plus the Spontaneous Combustion works really well on Broods too.

EDIT: Think this is the closest you can get to a Commander unit from Warhammer with Bolter and Chainsword, even though there is no Chainsword in the game.

[Emmental]

+20% Armour
50% Acid Resistance
-20% cooldown on shockwave

Resilience Perk +30% HP to bodyparts.

Storm Bolter + Force Sword

I used to use the axe for the cooldown bonus but I've come to prefer the sword because of the extra speed, better reach and wider swipe. Keep using the shockwave to keep anything particularly dangerous away like stalkers and broodlords. Lightning for turrets and psykers and combustion for scythe strain and broodlords, but your primary focus is melee knocking everything down.

[Waylander40K]

Upgraded lightning claws, make you a melee beast. The librarian has the advantage of being able to using chain lightning with them.

Claws do increase cool downs, for almost all classes. So take the -20% chain lightning .

The other advantage of claws with the lib is making him more easy to use. The bolter for him is poor and his force weapons are lame in melee. Claws give strong melee backed up with the warp.