The Moon of Mahaa-Kalaa achievements are some that can be very easily obtained when trying a new technique in the Gates of Hell. If you pick a Bat Within (assuming you haven't already purchased it) and choose to 'Try' it, you'll have an endless supply of slowly attacking Affinities to use.
To avert an attack with the Moon of Mahaa-Kalaa (an accessory you'll have to buy for 200,000 Halos), you just need to push the left stick towards an attacking enemy shortly before their attack connects.
It'll take a little practice, but using this technique, you should be able to get the timing down in a few minutes, allowing you to get all the Mahaa-Kalaa achievements fairly quickly.
If you've already purchased Bat Within, this will be a bit more difficult to obtain. Find a nice, easy spot (I recommend the Prologue or Chapter 1 on Very Easy) and try to practice. The same logic applies - before too long, you should get the timing down and be able to block an attack every time.