There needs to be some kind of energy regen/increase item added to the game. Seems like a large overlooked item niche. Nothing is worse than not being able to help you team as a Shen because of the poor energy cap/ regen. I would love it if there were some sort of energy support added.

Riot specifically stated, when they first created the Energy system, that there will NEVER--If you must, read that word about 40 more times--create an item that affects Energy. The furthest they would go with affecting Energy is runes, masteries and map-specific buffs.

And why would you complain about it anyway? Unlike mana champions, you're allowed to spam your spells early game without repercussions.

Energy champions are balanced around the fact there there NEVER are or will be any items for them.

they have a BETTER situation earlygame but they run out of energy faster lategame and must thus rpeserve it better lategame, they are created BALANCED around this concept.

There's only 5 champions that use energy in the game though, which is an incredibly small niche to create something for. They're completely different classes as well, Akali is an AP assassin, Zed is an AD Assassin, Lee Sin is a Bruiser/AD Caster/Jungler, Shen is a tank, and Kennen is a mage. The only way you could really design an item that they'd all find useful is to make it overpowered or have interesting mechanics that make other champions jealous by merit of the item having useless stats. And no matter how you split the 5 champions picking it up it becomes problematic. Only being viable on 5 champions isn't a wide range of champions at all - regardless of how you look at the viability of things like Hydra, Hurricane, and Rageblade all of them can at least put everything to use on close to half the champions in the game. And if it was useful enough all 5 energy champions picked it up, it would likely feel like a requirement more than decent item choice. If any of them could overlook the item for other things it would generally be seen as underpowered and completely unnecessary.

I wouldn't call energy as an overlooked niche so much as a nightmare for design purposes.

Probably the best you could hope for is some item(s) offering bonus to resource management for all champions regardless of what resource they use (fury, heat, energy, health, nothing), as it could potentially be useful enough to merit adding, but even then you're probably not going to make it feel viable on all manaless champions. At least you have runes and masteries to effect energy as-is.