In POE 3.21, which constructions can allow you to subdue the Boss easily? Which constructions are tank-type? If you are still hesitating, then Dominating Blow Guardian League Starter Guide is perfect for you. This guide focuses on using the Dominating Blow skill to summon minions and increase your DPS. With high survivability and a well-rounded kit, this build is perfect for league starters.

• Play Dominating Blow
• Levelling Up
• Gear and Gems:
• POE 3.21 Key Changes
• Build Defences
• Notes Tab
• Passive Tree

PoB Link: https://pobb.in/TXRIbaC1YL93!

↖ Play Dominating Blow

To play Dominating Blow, follow these steps: 

• Understand the basics: Dominating Blow is a skill that summons minions when an enemy that was hit by Dominating Blow dies. It also has a chance to summon a minion on hit against bosses. To start, use Dominating Blow to kill normal enemies and spawn your initial set of minions.
• Use utility skills: This build also uses several utility skills, such as Dread Banner, Convocation, Desecrate, Flesh Offering, and Rallying Cry. Until you have Unset Rings, prioritize these skills in the order mentioned above.
• Swap out gems when needed: Keep Desecrate, Frost Bomb, and Brutality Support/Melee Splash Support gems in your inventory to swap them out when needed. Desecrate can be used to re-summon your Spectres, while Frost Bomb can deal with enemies that have high-life regen. Brutality Support or Melee Splash Support can be used depending on whether you need damage or clear speed.
• Focus on summoning minions: Against bosses, your primary focus should be to summon your minions first by attacking with Dominating Blow. Once your army is summoned, use Desecrate and Flesh Offering to refresh the buff. Remember to also keep your army maintained by attacking to refresh your minions.
• Use Vulnerability: Until you have a ring or corrupted gloves with Vulnerability on hit, run a self-cast Vulnerability instead. This skill doesn't need to be linked to anything and should only be used on bosses or tanky rare monsters.

↖ Levelling Up

1. After killing Hillock, buy a Raise Zombie gem from Nessa and Smite from Tarkleigh, and get a shield or a second Driftwood Sceptre.
2. In the Submerged Passage, take either Summon Holy Relic or Holy Flame Totem as your quest reward and buy the other from Nessa. Also, buy a Summon Phantasm Support gem from Nessa.
3. Prioritize summoning Absolution minions and attacking with Smite until switching to Dominating Blow, which you can get in Act 3 after killing Gravicius.
4. Look for a usable staff starting around Act 7 and prioritize gear upgrades with life, resistances, and minion-related stats.
5. Take Herald of Purity as a quest reward in the Chamber of Sins in Act 2, and get a Raise Spectre gem before reaching the Ashen Fields in Act 7 to raise a Carnage Chieftain spectre.
6. Use whichever auras you have gem slots for, prioritize Vitality early on, and switch to Dominating Blow after Act 4 or later if desired.
7. Consider skipping staff nodes until getting a usable staff and taking the Spiritual Aid wheel before Resolute Technique.
8. Ascend in this order: Radiant Crusade > Unwavering Crusade > Bastion of Hope > Time of Need, but save Unwavering Crusade for last in Hardcore mode.
9. Combine Time of Need with a reduced curse effect gear craft or Consecrated Ground to get a 100% reduced effect of curses on you.
10. Be aware of enemies with increased curse effect.

↖ Gear and Gems:

• Very Early Mapping Sample Gear: This gear set is easily obtainable at the league start for 5 Chaos or less per piece. You can use a 5-link staff from the "The Flora's Gift" Divination Card and 4-links on other gear pieces until later. This Gear should be good enough to cap your resistances, provide damage, and defences to clear all the way into red maps.
• Mirror Tier Gear: This gear set is theoretically perfect Gear that is completely unrealistic ever to obtain. It gives an idea of what modifiers you should be looking for on Gear and what the potential top-end stats of the build are.
• Realistic Gear (Scourge): This gear set is the author's actual Gear from Scourge league, which was their secondary character. The author should have invested more POE 3.21 currency in this character, and it should be possible to obtain at least this level of Gear or better. Jewels do not update when changing item sets in PoB, so look at the Unused "Gale Song" jewel in the item list for an example of what to use on budget gear. The theory-crafted abyss jewels add a ton of damage, though, and you should aim for something similar to them.
• Realistic Gear: This gear set is the author's actual current Gear at the time of writing this guide. It was their league starter for this league, and they had all of this Gear at the end of the second week of the league. This level of gear progression should be manageable, even for more casual players over the course of a league.
• Aspirational Gear: This gear set is the author's actual Gear in the Lake of Kalandra league. This was their only endgame build in this league, so they focused on maxing it out. This Gear is the level that the author would consider the build "done" (minus a Mageblood). This build uses a lot of alternate quality gems, which may be expensive early on but aim to purchase them as quickly as you can.
• Gear Crafting: If you know how to craft, it is normally significantly easier and cheaper to craft most of the Gear for this build rather than purchasing it. You can mainly use Essences, Fossils, and Harvest crafts.
• Attributes: This build will be starved for Dex and Int without Gear. Either use the +30 nodes on the tree (Expertise and Ancestral Knowledge) or use the jewels which convert nearby Strength nodes into other attributes (Brute Force Solution and Fluid Motion) until you have high-end Gear.
• Weapon Choice: Consider using a higher DPS weapon and sacrificing some of the defensive/utility mods on the example staff. Higher DPS will make it easier to spawn your first set of minions and will increase the effectiveness of Rallying Cry.
• Juiced Delirious Maps: In very high-end content (juiced Delirious Maps), you may need to use a Writhing Jar to spawn your initial set of minions. You may need to unsummon your Carrion Golem first, as it tends to kill the summoned worms very fast.
• Sporeguard: It is possible to craft a better rare body armour than Sporeguard, but Sporeguard is a convenient package that gives a lot of things we want (and an extra Anoint).

↖ POE 3.21 Key Changes

• Removal of Mana Reservation Masteries: The Mana Reservation Masteries for Grace and Determination has been removed from the skill tree. To compensate for this, you can take the "Arcane Capacitor" passive wheel for the Mana Mastery that gives "12% Increased Mana Reservation Efficiency of Skills". Alternatively, you can drop Aspect of the Spider until you have more optimized Gear for reservation efficiency.
• Removal of Resistance Mastery: The Resistance Mastery for "20% Reduced Effect of Curses on You" has been removed from the tree. To fix this, you can get at least a "20% Reduced Effect of Curses on You" on one of your gear pieces. This is easiest on a Jewel.
• Removal of Life Mastery: The Life Mastery that gave a 10% increased Maximum Life / 10% Reduced Life Recovery Rate is gone, but it's not a big deal.
• New Armour Mastery: There is a new Armour Mastery that gives +1 all Maximum Elemental Resistances if your Armour/Helm/Gloves/Boots all have Armour. This is an easy take for us.
• New Armour and Energy Shield Mastery: There is a new Armour and Energy Shield Mastery that doubles Armour and ES from your body armour if your Gloves/Helmet/Boots all have Energy Shield and Armour. This is pretty strong if you meet the condition for it, but you will need to take either the "Faith and Steel" or "Sanctum of Thought" wheel to access it, costing 3-4 passive points (they are good passives, though, too).
• Nerf to Molten Shell: Molten Shell has been nerfed, but it's still our best Guard Skill.

↖ Build Defences

Dominating Blow Guardian build has a high life pool, small energy shield buffer, Divine Shield to maintain its high block chance, Recover Life on Block for the staff, high maximum resistances, Armor and Endurance Charges from the Inexorable passive, Cast when Damage Taken Molten Shell, decent life regeneration, stun immunity from Bastion of Hope, immunity to Freeze, Chill, Shock, and Curses from Soul of the Brine King and Anointed Flesh Wheel, and a Reduced Effect of Curses on you from the Guardian ascendancy point Time of Need.

↖ Notes Tab

The POB has an extremely detailed Notes Tab that includes an Endgame Crafting Guide for each slot of your Gear, advice on Gems and Playstyle, and a Leveling Guide that lists which Gems to take and when.

For early levelling, use Smite, Summon Holy Relic, and Holy Flame Totem with Summon Phantasm support in Act 1.

In Act 6, you will get access to all the Gems, and in Act 7, you will get Absolution. Use Absolution until the end of Act 4, where you will swap to Dominating Blow linked with Multi-Strike, Melee Splash, and either Concentrated Effect or Summon Phantasm.

↖ Passive Tree

The existing tree from the build guide and a variant that uses a large Cluster Jewel for more damage and focuses more on getting more life regeneration. The only Uniques used in this build are Spore Guard and Ashes of the Stars. For Specters, use Carnage Chieftain, Demon Harpy, and Arena Master. Several Alternate Quality Gems in this build add significant benefits and should be prioritized after acquiring Ashes of the Stars.

Conclusion:

The Dominating Blow Guardian League Starter Guide is a powerful and tanky build that is easy to gear. With high survivability and a strong kit, it's perfect for dominating the Path of Exile Crucible league. Utilize the detailed POB Notes Tab to optimize your playstyle and Gear.