Deckard Cain by baldursfire

Passive: increases mana regen of nearby allies.

To avoid looking too much like Li Li, Cain's potion will be activated by the allied unit themselves like a true Diablo potion, stacking on their number bar. lvl 1 has one stack but "Plated Belt" skill increases stacks to 4 based on role of the allied unit. Warrior get 4, Specialist 3, Assassin 2, friendly Support characters receive no benefit from "Plated Belt".

Identify an allied hero's weapon or armor granting them a random buff. The allied unit sees something like:

Bow of The Storm: attack speed 15%,
Hammer of The Whale: attack damage 15%
Sword of The Zodiac: spell damage 15%

While being granted anything from increased movement speed, damage -or even knockback, slow, vision, a charge of block. Identify could roll criticals in the form of identifying a legendary for double percents or yards revealed.

A level 16 skill will increase Cain's buffs to last until death (similar to blessing of the red). But can be re-rolled for a wanted effect. If lucio gets a legendary speed buff... Let it ride.

Disable an enemy basic ability. When cast, Disable affects the last basic ability used by the enemy, the next time the enemy tries to use this ability it will skip straight to a cooldown but at no mana cost.

Reveal all enemies and display the cooldown of their heroic ability overhead for 5 seconds.

(This is my weakest idea. I like a damage ult "staff of kings" or even Lorenado better)

Just your basic town portal, from your location straight to hearth, no channeling time. Unlimited uses by allies, one use by you. Cooldown begins when portal is closed. Portal closes only on return trip by Cain from hearth or his death.

HP restored to friendly units by the Hall of Storms after using Town Portal are tallied in Cain's healing statistics.