You can spam a lot of Call Lightning thanks to the Earth Mastery passive skills (which are completely broken with this build). It gives you infinite shield uptime, so you can focus on building your character around damage and mana regeneration stats. Every time you cast Call Lightning, you get Overload, which drains your HP very quickly. However, by casting Cyclone, you cleanse the Overload damage and get your mana and shield back. It's a very chill build to play once you get enough mana regeneration because you can tank most damage. There are other masteries you can combine, like Rogue, but they won't provide the same shield sustain. You might deal slightly more damage, but you will get one-shot much more often.

• 
  Poseidon's Trident

  stats

  • 15/30/45% increased Spell Damage
  • 4/8/12% Lightning Resistance
  • 30/5/10% Shocked Resistance

  completion bonus

  • Every 3s, 100% chance to apply Weakened to all enemies within 3m area
  • 9% increased Weakened Ailment Power

  
• 
  Vile Ichor

  stats

  • 3/6/9% increased Cast Speed

  completion bonus

  • 20% increased Spell Damage

  
• 
  Necrotic Bones

  stats

  • +12/24/36 Energy

  completion bonus

  • +4 Energy Regeneration per second

  
• 
  Necrotic Bones

  stats

  • +12/24/36 Energy

  completion bonus

  • +4 Energy Regeneration per second

  
• 
  Selene's Moonlight

  stats

  • 15/30/45% increased Spell Damage
  • +5/10/15% Cold Resistance

  completion bonus

  • Killing grants +3 Energy Regeneration for 4s (stacks 4x)

  
• 
  Hypnos' Calm

  stats

  • 4/8/12 Energy Regeneration per second
  • +30 Energy Reserved

  completion bonus

  • 20% increased Energy Regeneration while below 50% Energy

  
• 
  Vile Ichor

  stats

  • 3/6/9% increased Cast Speed

  completion bonus

  • 20% increased Spell Damage

  
• 
  Centaur Hoof

  stats

  • 3/6/9% increased Movement Speed

  completion bonus

  • 10% increased Movement Skill Cooldown Rate

  

What I do is hold the right mouse button to constantly spam Call Lightning, while using the left mouse button to cast Cyclone every few seconds. Basically, it's a two-button spam build.