[2.6] HC Explosive Arrow Champion

Mainhand Weapon: Quill Rain (Clearspeed): Explosive Arrow, Greater Multiple Projectiles, Fire Penetration, Increased Area of Effect, Less Duration (6th link can be either Empower level 4, Slower Projectiles or Life Leech. Empower level 4 is more up front DPS for Clearspeed).
Offhand Weapon: Quill Rain (Boss Killer): Explosive Arrow, Fire Penetration, Concentrated Effect, Chance to Ignite, Less Duration (6th link can be Slower Projectiles, Empower level 4 or Life Leech. Slower Projectiles is more damage as a Boss Killer).
Quiver: Rare: Life, Resists, Attack Speed, +1 Arrow
Helm: Devoto's Devotion: CWDT (lvl 10), Immortal Call (lvl 12), Decoy Totem, Increased Duration
Chest: Kaom's Heart
Gloves: Null and Void or Rare: Life, Resists, Attack Speed: Blink Arrow, Blood Rage, Vaal Haste, Increased Duration
Boots: Rare: 30% Movement Speed, Life, Resists: Frenzy, Greater Multiple Projectiles, Curse on Hit, Flammability
Belt: Perseverance
Ring 1: Rare Opal: Fire Damage from Essence of Anger, Life, Resists
Ring 2: Rare Opal: Fire Damage from Essence of Anger, Life, Resists
Amulet: Rare Marble: Fire Damage from Essence of Anger, Life, Resists
Note: Try to get either +Lightning or Cold damage to attacks on either a ring, amulet or gloves to proc Elemental Equilibrium. DO NOT get +Fire damage to attacks on any piece of gear.

Prefix: % Increased Life, Fire Damage. Suffix: Projectile Damage, Area Damage, Resists

Pathing is up to you. You can always go for Explosive Impact, Savagery or Arsonist early on if you don't have enough damage from gear.
https://www.pathofexile.com/passive-skill-tree/AAAABAQDAAHcBLMFLQthDF8NzQ48FCAUTRRxFm8YkRo4GmwbRhynHM4c3CSqJbwnLyj6K1AuUzLRNZI26TpSOuE8BTwtPfxDMUVHRZ1Hfk3jUEdTUlOlVkhYY1nzXzlfP2VNaGVo8m87cql07XXLdqx343gNeWh674IHg1-DzITZivCLpozPjX6PGpBVmK2a4Jstna6f36IAplenCKlurKqtja9sr6ewq7Xytz63triTvJ-9Nr6nwBrAZsEExFjEgsT2xq7G2M9-02_YJNi92XzawdtP37_gw-Nq6UbqGOpi6-7vDu988B_yQfJF8932SPcy-Ov8S_4K_lT-jw==

I plan on grabbing 'Inspirational' first to help myself and my team level (Unless one of my teammates also grabs it). Once I get to Cruel lab I will then pick up 'Unstoppable Hero' and likely respec 'Inspirational' into 'Fortitude'. For Merciless I will pick up 'Inspirational' again and lastly will grab 'First to Strike, Last to Fall' from Uber lab.

Helmet: 40% Explosive Arrow Damage
Gloves: Commandment of Reflection
Boots: 10% increased Movement Speed if you haven't been Hit Recently

Normal: Help Oak
Cruel: Skill Point (Attack Speed is also good early on but I find I have enough with decent gear)
Merciless: Help Kraityn for the extra Frenzy Charge

Seething Divine Life Flask of Staunching
Seething Divine Life Flask of Heat
Alchemist's Quicksilver Flask of Adrenaline
Rumi's Concoction, Atziri's Promise or Dying Sun
The Overflowing Chalice
-Flasks may change depending on what upgrades are made in 2.6. With a legacy Kaom's Heart and 15k life I may try out Blood of the Karui and / or Forbidden Taste