Consider the following: You're using your Baemore or some other sweet heavy weapon, but your enemy immediately gets parried. So what do you whip out to riposte them with? Dagger or Mail Breaker?
Most would think the Dagger is good enough, but IMO, it's this sucker right here. Riposte with the Mail Breaker and then 2H it to finish off the guy. Because it has a really fast version of Shield Splitter, L2 rollcatches, and its R2s can be used to rollcatch, and just braindead spamming the first R1 stab by microwalking/blocking can rollcatch. So satisfying.
(or you can just weaponswap to gundyr's after dagger riposte idk f u)