Crack of the Heavens

Crack of the Heavens is effective, but more challenging to mitigate and somewhat less necessary than other sunder charms. Unlike Flickering Flame for Flame Rift, Bramble for Rotting Fissure, or Thawing Potion for Cold Rupture, there is no simple solution for the penalty Crack of the Heavens imposes on one of the game's most critical resistances.

The Conviction aura granted by Infinity is capable of "breaking" the Lightning Immunity of most enemy types (and fails to break the immunities of a number of Fire- or Cold-Immune enemy types). The -X% Enemy Lightning Resistance found on items such as Crescent Moon, Griffon's Eye, Thunderstroke, or the aforementioned Infinity works equally well regardless of whether a target's Lightning Immunity was sundered by Crack of the Heavens or broken by Conviction. Thus, in such contexts, the difference between using a Crack of the Heavens or not is a modest increase in damage output at the cost of a significant penalty to durability.

None of the "Original Sundering Charms" ( Black Cleft, Bone Break, Cold Rupture, Crack of the Heavens, Rotting Fissure, Flame Rift) can be obtained in RoW (Reign of the Warlock).

They have been replaced by the new "Latent Sundering Charms":
Latent Black Cleft
Latent Bone Break
Latent Cold Rupture
Latent Crack of the Heavens
Latent Rotting Fissure
Latent Flame Rift