Mercenary is clearly inspired by Punisher from Marvel Heroes but isn't as fun to play

The Punisher from the late, great (but back with private servers!) Marvel Heroes Omega is a pretty clear inspiration for PoE 2's Mercenary - he has some shotgun skills, some assault rifle/machine gun skills, some rocket/grenade skills, and a reload skill that grants a damage buff. He even has a gas grenade that explodes when ignited

Thing is... Punisher is actually fun and smooth to play while Merc is clunky and awful.

What made Punisher awesome?

Simply put, the Ammo resource and Rapid Reload. Whereas the default resource in the game was Spirit (which worked pretty much like mana), several heroes had a custom resource with its own mechanics. Punisher's Ammo resource didn't passively regenerate and couldn't be leeched, meaning you had to rely on the Rapid Reload skill to replenish it.

Rapid Reload had a 15 second cooldown (reduced to 10 seconds if used while at 25% of max Ammo or lower) and would reload 100% of your Ammo, refresh all your cooldowns, and give you a 20% damage buff until your next reload. You could also trigger a lengthy automatic reload sequence by running out of Ammo entirely, at which point you'd have to rely on your basic attack until it was done.

That's it. Simple, straightforward, and easy to manage. No swapping between ammo types - a skill either used your Ammo pool or it had "charges" (a number of uses before going on cooldown). Reloading (either automatically or via the Rapid Reload skill) restored all your Ammo and reset all charges/cooldowns (other than Rapid Reload itself). And if you were carefully managing your rotation, you got a permanent 20% damage buff on all skills.

Now imagine if Merc worked like this. Instead of the clunky, painful mess of managing multiple separate ammo pools, dropping hundreds of mana at once to reload, and waiting for grenade cooldowns to come back one at a time, you just spend mana per shot, manage your skill use and time it so you hit the reload button at the right time.