Challenges - Act II

Good Eye (10 Points)
Kill Belial without getting hit by his projectile or meteor attacks

This is when facing Belial in the "Lord of Lies" quest.

Why'd it have to be snakes? (10 Points)
Kill 10 Veiled Sentinels in 30 seconds while fighting Belial on Nightmare difficulty or higher

Those Veiled Sentinels Spawn when you go to fight Belial

Fist Missed (10 Points)
Kill Belial without getting hit by his fist attack

Best way to get this one is to be constantly on the move during this battle.

Bad Breath (10 Points)
Kil Belial without getting hit by his breath attack on Inferno Difficulty

Belial's Breath attacks are the ones in which green fire comes out of his mouth. This is performed in a wide arc, so move away from it as soon as you see Belial perform this attack.

Hiding in Plain Sight (10 Points)
Disrupt both Coven Illusions in the Howling Plateau in under 4 minutes

As soon as you enter the Howling Plateau in the quest "Shadows in the Desert", you get the objectives to disrupt two secret rituals. Immediately start looking for the entrances to the Hidden Conclave and the Secret Altar. There are footsteps on the ground which can lead you to the entrances, or just scout.  When you enter the first of those dungeons, immediately shoot the ritualists, and as soon as the first objective is complete, don't bother killing the rest - just go and search for the second hideout.

Hero of Alcarnus (10 Points)
Free all the prisoners in Alcarnus

This is related to a Bonus objective while doing the "City of Blood" quest. The bonus mission requires you to save 8 caged prisoners, but there are actually 10 caged prisoners in that area, as well as some more in the Alcarnus Cellar. Scout the area for the Alcarnus Cellar entrance after freeing all the prisoners outside, enter the cellar, and free the rest of the prisoners inside to get this achievement.

Lord of the Flies (10 Points)
Achievement Rewards: Banner Sigil
Kill Maghda without getting hit by her insect attack

Got a Head (10 Points)
Find the head of Zoltun Kulle within 120 seconds of entering the forgotten ruins

When entering the forgotten ruins, ignore everything else and go straight to the head

Big Trouble in Talking Barrel (10 Points)
Hear everything Covetous Shen says before you break him out of the barrel

Kulle Duel (10 Points)
Achievement Rewards: Banner Accent
Kill Zoltun Kulle without killing either of his eternal guardians

Hero of Caldeum (10 Pts)
Evacuate 20 Caldeum refugees to the sewers in one game

This is during the quest "The Scouring of Caldeum". Some refugees are in refugee carts.

Watch your Step (10 Pts)
Complete the Caldeum uprising without taking any damage from the poison wells.

Sandskimmer (10 Pts)
Complete Act II in under 1 hour

For this one, you'll have to speed run from one main quest to the next, ignoring story, bonuses, and events.