Path of Calamity Hybrid Build
I shared this build a while ago, and have since come up with an alternative to it that I have found to be particularly useful in RvR when playing in open warbads:
Path of Calamity Hybrid Build (Open Warband)
The Path of Calamity offers a nice mix of long-range single-target and mid-range area-of-effect spells which can create versatile builds to adapt to many situations.
This makes it ideal in open warbands where the size of the warband and amount of support you receive can vary greatly.
The build features many defensive tools that can help make you more self-sufficient and your party more survivable. Absorb Vitality helps to keep you alive in situations where healers are scarce. Tapping the Dark and Wind-woven Shell significantly improve the sturdiness of your group.
In terms of single-target damage the build puts an emphasis on mobility and damage over time, with Chilling Gusts greatly increasing the damage output of Chillwind and Ice Spikes. Absorb Vitality adds extra pressure, and Hand of Ruin can be used for heavy sustained damage or as part of bursting rotations. Frozen Fury is self-explanatory and increases damage output of both single-target and area-of-effect spells. Gloom of Night can be cast for added single-target pressure on tough targets.
Area-of-effect damage comes from a mix of damage over time and direct damage abilities. Ideally, areas are first primed with heavy hitting DoTs like Ice Spikes and Gloom of Night (and preferably also blasting potions), after which direct damage is applied with Pit of Shades and Infernal Wave.
This combination is especially potent in chokepoints and keep sieges. In defensive funnels, a tactic can be swapped out for Triumphant Blasting. This somewhat overlooked tactic can turn Sorc into the lynchpin of keep and fortress defenses.
In fights where mobility is key, focus on Ice Spikes, Infernal Wave, spreading Chillwind on multiple targets and the occasional Surging Pain (hits hard due to Frozen Touch procs. Also procs Tapping the Dark.) Only cast Gloom of Night when opportunities present themselves.
The Crippling Terror Morale 4 is optional, though I have found it quite unique and useful. In keep and fortress sieges it can be used at the start of an enemy push on the enemy healer blob to cripple their healing output for a full 7 seconds. It can also be cast on enemy ranged blobs to cripple damage output instead. Another interesting use is for assaulting posterns, where this M4 can be used to disable the melee blob that is usually stacked on the warp-in point.
Lastly, it is possible to combine this build with full Warlord or full Offensive Sovereign. The two extra skillpoints allow you to pick up Impending Doom for quick Dark Magic generation and added single-target burst. In addition, the 7-piece On Hit procs are very potent in large-scale fights where your direct damage AoE will spread 4% (Warlord) and 5% (Offensive Sov) increases in damage taken. The 8-piece bonus is optional.
Going full Defensive Sovereign is also an option, although it does not give access to Impending Doom, the 7-piece On Hit snare is very strong in large fights. The 8-piece ability that provides a 50% increase in AoE radius is also great, however due to a bug it does not apply to Pit of Shades and Gloom of Night, which defeats most of its purpose.
Even Bloodlord can be considered, as it provides On Hit effects that reduce healing received by 25%, which is potentially very effective in keep and fortress sieges.
"I watched a snail crawl along the edge of a straight razor. That's my dream; that's my nightmare. Crawling, slithering, along the edge of a straight razor... and surviving." - Colonel Walter E. Kurtz