Skill Gem	Beneficial Support Gems
Explosive Shot	Ignition, Magnified Effect, Pierce
Gas Grenade	Scattershot, Fire Penetration, Inspiration
Ripwire Ballista	Ruthless
Explosive Grenade	Fire Infusion, Primal Armament, Magnified Effect
Oil Grenade	Ignition, Magnified Effect
Flash Grenade	Overpower
Galvanic Shards	Lightning Infusion, Pierce
Glacial Bolt	Fortress
Herald of Ash	Clarity, Vitality

Gas Grenade poisons a wide area (detonatable with a Detonation skill), while Explosive Grenades explode after a delay or detonation. Explosive Shot detonates these grenades for massive AoE and single-target damage. Ripwire Ballista distracts enemies, and Glacial Bolt controls hordes. Oil Grenade excels in AoE but is often outclassed by Gas Grenade; consider Glacial Bolt for exploration and Oil Grenade for bosses. Galvanic Shards efficiently clears hordes. Herald of Ash ignites nearby enemies upon overkill damage.

The listed support gems are generally level 1 or 2, readily accessible before Act 3. Prioritize gem interactions; use available support gems until obtaining the recommended ones. Employ Lesser Jeweller's Orbs to add support gem sockets to Explosive Grenade, Explosive Shot, and Gas Grenade.

Crucial Passive Skill Tree Nodes for Leveling

Focus on these three key passive skills: Cluster Bombs (adds projectiles, extending grenade explosion time), Repeating Explosives (chance for double explosions), and Iron Reflexes (converts evasion to armor, countering Sorcery Ward's armor reduction).

Sorcery Ward (Witchhunter Ascendancy, the best Mercenary Ascendancy for leveling) provides a strong non-physical damage barrier but halves armor and evasion. Iron Reflexes mitigates this drawback. Prioritize Iron Reflexes after reaching the tree's edge, detouring slightly left to grab it near an attribute node. Also seek Cooldown Reduction, Projectile & Grenade Damage, and Area of Effect boosts. Crossbow skills, armor/evasion nodes are secondary; prioritize if needed.

Recommended Items and Stat Priorities

Upgrade equipment strategically; only replace items with significantly superior modifiers. Prioritize your crossbow – a strong crossbow upgrade dramatically enhances power. Mercenaries balance Dexterity and Strength, along with Armor and Evasion. Seek gear boosting these stats, plus Physical/Elemental Damage, Mana on Hit, and Resistances. Rarity, Movement Speed, and Attack Speed are beneficial but not mandatory.

Ideal modifiers include:

• Dexterity
• Strength
• Armor
• Evasion
• All Elemental Resistances (except Chaos)
• Increased Physical Damage
• Increased Elemental OR Fire Damage
• Attack Speed
• Mana On Kill OR Hit
• Life on Kill OR Hit
• Rarity of Items Found
• Movement Speed

A Bombard Crossbow significantly simplifies leveling by adding an extra grenade projectile to grenade skills. Acquire and utilize these crossbows for crafting opportunities.