Kira's Guardian, stick a 40/15 jewel in it if you want damage.

kiras deals big dmg already so maybe um it for more res or cham for cbf

Insight and fort are trash on a merc for a hammerdin. You don't need meditation, single point in redemption solves your mana problems. Merc doesn't need 300% ED, he benefits from your high level concentration. Use this setup:

ETH reaper's toll - Ber
ETH treachery
Guillaume's helm - Cham

Good DPS, CBF, 50% CB, 50% DS, second highest IAS breakpoint.

Also, after maxing hammer and synergies plus conc you can easily max holy bolt which shares a synergy with hammers.

Best wave 2 strat: lay a hammer field and switch to redemption to redeem skeletons. Position yourself between Baal and your merc, that way he casts decrepify on you and not him. Let him begin attacking and hit the rest with holy bolt.

Smite/holy bolt them.

finally decided to take this advice and my merc is 10x better. 7k damage instead of 11k, but the cb, ds and ias make up for it. not gonna put a ber in the thresher yet as it's early in the ladder it's very expensive, did put a 15 ias jewel in to hit the next ias bp for my merc. thanks for the advice.

Glad the setup is working out for you.

Btw, you need 30% extra IAS with treachery to hit the next bp. (Breakpoints for jab are 42 or 75) So, that IAS jewel is not doing anything.

Two options:
- if you haven't Cham'd your Guillaume's yet, get two IAS jewels to hit bp.

- if you have Cham'd your Guillaume's, get a ED% jewel in the meantime.

Yep its either 2ias jewels or cham/ber

You could put something like Amn rune in Reapers but only if you have cham in guills. If you cant afford cham either just use two ias jewels

yeah i've already cham'd the guil and shael'd the reapers, should i hel + tp the reapers and put amn or ber in?

Yes because Shael does nothing. Amn was just an chean example. Its not bad either but overkill obviously. Shouldnt spend anything too expensive if you are gonna get ber in it one day anyway.