New Unique Map and mechanic for U2

[HeadphonesEnjoyer]

At a certain point (maybe Z350+) a new unique map may be unlocked, called Grotto (or a similar name).
It will allow the player to access it once per Portal and start delving down(I admit it may be slightly inspired by POE content) to collect Ores to enhance their Equipment.

A certain special trait of the map may be that you start from the top and work your way to the bottom opposed to the regular bottom to top.

Every 10 cells you get to "save" whatever you've mined and transport it via a shaft up to the surface in order to spend said ore. Manually leaving once the map gets progressively harder may be made desirable to maximize gains as failing the map may mean less brought material.

The theme can also be changed. For example, instead of mining, it could be a journey through the Underworld river Styx or whatever.

The actual upgrades can come in the form of tokens (a bit like nature in U1). When you upgrade a piece of equipment it removes the damage/hp bonus for this piece(kinda like Pandemonium), but provides a separate specialized bonus instead. With enough upgrades the dmg/hp gains can be brought back partially and later - fully.
You could be incentivized to, first, upgrade one piece of gear only, or if beneficial, have builds with more than one partially upgraded if farming for a specific thing for example.

Potential upgrades: (can be adjusted or changed entirely)

• Shield - allows you to attack first always and then again after the enemy attack - like deadly void maps, but you benefit. Could also make poppin off and smashing spawns "lame" (provide extra Rn gain, but not have the special effect).
• Dagger - apply a small percentage of poison (like U1 nature)
• Boots - further boost the Agility perk by X%
• Mace - apply crushing attacks that would work like Nova, but for you within a few stacks
• Helmet - apply "visor" effect letting you gain more trinkets, seeds, Scruffy XP, and Dust by a certain %
• Polearm - armor penetration - deal bonus dmg % to mutated cells - nova, random, compressed or rage
• Pants - deep pockets - boost greed, motivation, looting, observation resource gain (basic, no extra radon, maybe?), and packrat by a %
• Battleaxe - add an executioner effect - cells with % remaining health get killed instantly (limited for plagued or bosses)
• Shoulderguards - maybe a small x% change to dodge enemy attacks
• Greatsword - add the summon Squireimp ability - squire attacks after you dealing x% of your dmg and tanks the next hit giving you x% dmg reduction
• Breastplate - provides x% prismatic shield back as hp%
• Arbalest - Trigger happy ability - boosts crit chance and crit dmg
• Gambeson - Boost Gene Attack and Gene Health mutators by a x%