Here's a concise Grenade Mercenary Leveling Guide for Path of Exile 2, detailing strategies for each act, recommended gear, and skill progression to Path of exile currency make the most of this fun and explosive build.

Overview
Leveling as a Grenade Mercenary offers a satisfying playstyle involving explosive projectiles and area control. While it's not the fastest, the build is versatile and enjoyable, especially with its utility-focused grenades. The downside is its reliance on a multi-button rotation, which can be mitigated by specific unique items.

Act 1: Starting Strong
Act 1 is the most challenging phase due to POE currency buy limited AoE capabilities. Here's how to start:

Single-Target DPS:

High Velocity Rounds + Double Barrel + Martial Tempo
Flash Grenade + Scattershot + Overpower
Clearing Tool:

Galvanic Shards + Lightning Infusion + Pierce
Optional: Permafrost Bolts + Ice Bite for freezing enemies.
Utility Skill:

Herald of Ice or Herald of Thunder for added damage and utility.