In the dynamic world of Guild Wars 2's Soto Expansion, mastering the art of PvE builds is essential for solo players and small groups alike. In this guide, We'll rank the best PvE builds for open world events in Guild Wars 2 after the Soto expansion.  Evaluating their self-sustainability, ease of play, and overall effectiveness. 

• Necromancer
• Warrior
• Mesmer
• Thief
• Ranger
• Elementalist
• Engineer
• Guardian
• Revenant

↖ Necromancer

• Harbinger (A Tier): Harbinger offers the highest damage output among Necromancer specializations but relies heavily on outgoing condition damage for healing. To maximize its damage and sustain, you must stay within melee range while in Shroud.
• Scourge (S Tier): Scourge is a comfortable and easy-to-play Necromancer spec. It excels in removing conditions, generating barriers, and has a straightforward rotation. While it may have slightly lower DPS than Harbinger, its user-friendliness makes it a top pick.
• Reaper (A Tier): Reaper boasts a clear and easy-to-learn rotation with better DPS than Scourge. It excels in bursting down groups of mobs or tough enemies with its condition damage.

↖ Warrior

• Berserker (B Tier): Berserker is an easy-to-play warrior spec with decent DPS and sustain. However, it's unforgiving for mistakes, so precision is essential.
• Spellbreaker (C Tier): Spellbreaker relies on using a hammer to break defiance bars and generate DPS buffs. While it offers average DPS and semi-decent sustain, it's not as forgiving for errors and requires precise timing.
• Bladesworn (S Tier): Bladesworn stands out with the highest damage among warrior specializations. It maintains stability and offers a lot of crowd control and high sustain. However, it may take time to master its playstyle.

↖ Mesmer

• Mirage (S Tier): Mirage excels in dealing high DPS while being able to pierce and bounce attacks to multiple targets, making it excellent for cleaving mobs and controlling crowds. A top choice for taking on open world content.
• Virtuoso (C Tier): Virtuoso can block incoming damage with a shield and heal with a Defender Relic, but it lacks damage compared to other mesmer specs. It's unforgiving for mistakes, making precise timing essential.
• Chronomancer (D Tier): Chronomancer, unfortunately, underperforms in both damage and sustain compared to other mesmer specializations.

↖ Thief

• Specter (S Tier): Specter is an easy-to-play thief spec with decent DPS and sustain. It can deal damage from range, generate a second health bar, and use skills to absorb incoming attacks effectively.
• Daredevil (D Tier): Daredevil struggles with low DPS output and lacks passive healing. It offers extra endurance for dodging but is unforgiving when mistiming dodges.
• Deadeye (S Tier): Deadeye excels with high DPS and high self-sustain. Its simple rotation and focus on ranged combat make it a formidable open world choice.

↖ Ranger

• Druid (A Tier): Druid offers high DPS, AoE potential, and condition cleanse. However, it has lower passive healing and requires stopping DPS to regenerate.
• Soulbeast (S Tier): Soulbeast is the easiest Ranger spec to play. It delivers high damage and sustain, making it a top pick for open world PvE.
• Untamed (B Tier): Untamed is complicated to play but provides high damage and incredible sustain when using Ambush attacks. It's not as forgiving for mistakes and may take time to master.

↖ Elementalist

• Catalyst (S Tier): Catalyst is the strongest elementalist specialization, offering high DPS and sustain. While it's not easy to master due to its fast-paced rotation, it's incredibly effective in open world content.
• Tempest (S Tier): Tempest is the more accessible version of Catalyst, offering slightly lower damage but an easier rotation with long animations.
• Weaver (B Tier): Weaver provides decent DPS, but it's easy to play thanks to its simple rotation. It can burst mobs faster but has lower sustain.

↖ Engineer

• Holosmith (A Tier): Holosmith is easy to learn, offering decent damage output and passive healing when leaving Photon Forge. It can burst groups of mobs with ease.
• Mechanist (S Tier): Mechanist stands out with high DPS, good sustain, and access to both quickness and alacrity. It's easy to play and provides a solid open world experience.
• Scrapper (C Tier): Scrapper can generate its own boons and offer some sustain, but its damage output is relatively low, especially in a Berserker gear setup.

↖ Guardian

• Dragon Hunter (D Tier): Dragon Hunter lacks the ability to generate its own boons, has no passive healing, and is unforgiving for mistakes, resulting in its underperformance.
• Firebrand (C Tier): Firebrand can use its tomes for DPS, healing, or boons, but it struggles with low DPS, and you must choose between these options due to the page ammunition system.
• Willbender (A Tier): Willbender is a powerful Guardian spec for open world content. It can use all F skills simultaneously for DPS and sustain. However, it requires a fast-paced skill rotation.

↖ Revenant

• Herald (S Tier): Herald is simple to play, has good DPS, and can maintain many boons, making it a top choice for open world PvE.
• Vindicator (S Tier): Vindicator is extremely forgiving for mistakes, offering decent damage and exceptional tankiness. It's perfect for new players or those seeking an easier experience.
• Renegade (A Tier): Renegade matches Herald's damage but excels in burst damage and AoE skills. While it provides high DPS, it has slightly lower passive sustain.

Conclusion:

In summary, these tier rankings consider various factors like damage, sustain, and ease of play. It's essential to choose a build that suits your playstyle and preferences. With the right setup, you'll be well-prepared to conquer the open world in Guild Wars 2's Soto Expansion. Enjoy your adventures and may your chosen build serve you well!