Original Post — Direct link

I went through the character Json to figure out why exactly Shang Chi special is doing the heal.

His heal is not actually heal, but he does negative damage to your allies. -1000% damage to all allies in fact.

Since the heal is damage, it is affected by defense up, defense down, offence up on Shang Chi, Vulnerable and damage reduction.

He can also Crit on this attack and does extra healing cause of the Crit damage. That is why healing is not consistent through out. His heal doesn't seem that powerful in alliance war defense cause Luke Cage gives extra 50% health to all H4H allies + Med bay bonuses, and when every one has charges, they also have damage reduction.

Update : Scopely already updated the special. so this post is basically invalid now.

But for those who are wondering what the comments about colleen wing being an ally and such, Scopely intentionally added the code to deal negative damage if Colleen Wing is an ally(this time just -30% so it is negligible) and added heal on top of that. The Colleen Wing portion didn't exist before and it did -1000% in stat_modifier block.

{
    "action": "proc_remove",
    "category": "debuff",
    "count": [
        1,
        1,
        1,
        1,
        1,
        1000,
        1000
    ],
    "stat_modifier": [
        {
            "apply_if": {
                "count": {
                    "if": "greater_or_equal",
                    "than": 1
                },
                "count_filter": {
                    "character": [
                        "ColleenWing"
                    ]
                }
            },
            "delta": [
                -30
            ],
            "stat": "armor_pierce_pct"
        }
    ],
    "target": {
        "filter": {
            "traits": {
                "has_any": [
                    "HeroesForHire"
                ]
            }
        },
        "limit": 10,
        "relation": "ally",
        "type": "random"
    },
    "visualid": "special_procremove"
},
{
    "action": "proc_remove",
    "category": "debuff",
    "count": [
        1,
        1,
        1,
        1,
        1,
        1,
        1
    ],
    "stat_modifier": [
        {
            "apply_if": {
                "count": {
                    "if": "greater_or_equal",
                    "than": 1
                },
                "count_filter": {
                    "character": [
                        "ColleenWing"
                    ]
                }
            },
            "delta": [
                -30
            ],
            "stat": "armor_pierce_pct"
        }
    ],
    "target": {
        "filter": {
            "traits": {
                "not": {
                    "has_any": [
                        "HeroesForHire"
                    ]
                }
            }
        },
        "limit": 10,
        "relation": "ally",
        "type": "random"
    },
    "visualid": "special_procremove"
}
External link →
19 days ago - /u/CM_Cerebro - Direct link

We're still working on this - really appreciate the patience in the interim.