Logan's vs Demon's Catalyst ? (dark magic)

I'm creating this topic because I haven't found any answers and the chracter builder doesn't count the scaling of the catalysts ... The character I'm working on will have 50 strength and 50 intelligence. Will the Demon's Catalyst be better for dark magic than Logan's Catalyst, since it scales with STR and DEX (D/D/B/-) ?

Oh, and another little question : what's the AR of the Manus Catalyst R2 ?

Thanks for your help !

The scaling is only for melee attacks. Demon's Catalyst is never the best catalyst, unless you want it specifically for the melee attack.

With 50 intel your best choice would be logans catalyst. The magic adjust is a lot higher and it doesnt half your spells. The demons catalyst doesnt half either but its not as good.

I'll stay with Logan's then. Thank you !