Coming back to Diablo after sum years. I built a mosaic sin last ladder and had tons of fun with it and now I'm thinking about building a bear assassin. Any advice or tips for hitting that 12.5 attack breakpoint

i have no idea but im here to congratulate you on your first post

first post, knows to post in strategy n guides... and in a clan... multi alert

Well first thing, you cannot reach 2 fpa attack anymore which is 12,5 attacks per second.

You can reach maximum 4fpa which is 6,25 attacks per second.

USE warren ias calc.

You can forexample use mark of the bear helm.
You can use bos.

Now you have a huge boost in dr%, skill ias, and the helm itself gives cb,cnbf, and some @ res.

So if you have forexample mark of the bear and level 30bos you need 58 ias for 4fpa.
That means that you dont need Fana merc in my eyes, as well as you may run any claw such as mosiac etc if u want as long as its runic talons.

As a mosiac bear which is slower than a kickmosiac u can use infinity merc.
But as a physical bear you can use eth reapers merc and on top of that use maxed bladeshield with syntenergies.

Then hl + Loh gives you 40 of those ias.
That means ur claw need 20ias from claw..

As a cheap effective option both plague and fury is viable claws here.
Gores as boots.
Either enigma, duress or forti armor.
Metamorphosis helm.
Stormshield
Arach or strings belt
And u can go 2 x 10fcr adds rings if arach and enigma.

This will Grant you high stats, high ds, decent cb, 4fpa, fast runspeed, up to 40fcr, high bladeshield damage, might from merc, ctc decreap from merc etc.