Did some magic burst testing on Apex crabs. AAEV, Ulmia and Yoran-Oran trusts, max Gain-INT. Self SC CDC>CDC>Light>Thunder V, no weather/neutral day. Only have NQ Ea, here's the set I used:
ItemSet 375949
Amalric hands/feet path D, Cape INT +30/Mag. Acc +20 Mag. Dmg. +20/Mag. Att. Bonus +10
First, MB Test set vs Locus ring swapped in instead of Freke
MB Test: 57001
Locus: 56922
Got the same results 3 crabs in a row.
Next, MB Test vs Vitiation Boots +3 instead of Amalric Nails +1
MB Test: 57001
Vitiation Boots +3: 55326
Third, MB Test vs R15 Metamorph Ring +1 instead of Freke
MB Test: 57467
Metamorph Ring +1: 57041
Lastly, MB Test vs Jhakri Ring instead of Freke and Jhakri Feet +2 instead of Amalric Nails +1
MB Test: 56609
Jhakri Ring/Feet: 53655
Edit: Forgot to add in Maxentius MB bonus on last test totals and was way overcapped on MB bonus damage, therefore Jhakri ring was doing basically nothing. Added one more test with just Jhakri Pigaches +2 swapped in
MB Test: 56609
Jhakri Pigaches +2: 54963
Looks like Mujin/Locus ring combo are not very far behind Freke/Mujin. Metamorph Ring is also a good contender.
Also did some testing a week ago with NQ Ea Pigaches. Don't have the numbers handy, but they were about 5k damage behind MB test set. They are so bad in fact that NQ Jhakri Pigaches beat them out.
EDIT: Updated with part 2 of testing
Jhakri Ring instead of Freke Ring
MB Test: 57467
Jhakri Ring: 56793
Some extra testing:
NQ Ea Pigaches instead of Amalric Nails +1
MB Test: 56609
Ea Pigaches: 51733
NQ Jhakri Pigaches vs NQ Ea Pigaches
Jhakri Pigaches: 52107
Ea Pigaches: 51733