Step 1: Identify the relevant industry
Based on the provided facts, A2A ENERGIA S.P.A. operates in Italy and is a subsidiary of A2A S.p.A., a multi-utility company. The facts show significant revenue from electricity/gas (Raw Materials and Consumables Used being the largest expense) and it fits the "Regulated Utilities" or "Unregulated Power And Gas" sector. Since it demonstrates characteristics of a multi-utility with regulated and unregulated operations, we apply the Regulated Utilities/Unregulated Power and Gas guidelines, utilizing the baseline formulas provided with standard adjustments for leases, pensions, and other debt-like items.

Step 2: Estimate 2021 Adjusted_EBITDA
Formula: Adjusted_EBITDA = EBITDA (reported or reconstructed) + adjustment_leases + nonrecurring_losses - nonrecurring_gains ± pension_adjustments ± joint_venture_proportional_EBITDA ± other_normalization_adjustments
Reported EBITDA (Gross Operating Income) 2021: 1,428,000,000 EUR
Result From Nonrecurring Transactions 2021: 0 EUR
Since specific lease, pension, and JV adjustments are not explicitly quantified in the facts other than standard operating expenses, we rely on the reported EBITDA.
Adjusted_EBITDA (2021) = 1,428,000,000 EUR

Step 3: Estimate 2021 FFO
Formula: FFO = Adjusted_EBITDA - cash_interest - cash_taxes
Cash Interest (Interest Paid Classified As Operating Activities) 2021: 80,000,000 EUR
Cash Taxes (Income Taxes Paid Refund Classified As Operating Activities) 2021: 165,000,000 EUR
FFO (2021) = 1,428,000,000 - 80,000,000 - 165,000,000 = 1,183,000,000 EUR

Step 4: Estimate 2021 Adjusted_Debt
Formula: Adjusted_Debt = (reported_debt + leases + pension_deficit + guarantees + hybrid_debt_portion + other_debt_like_items) - eligible_cash
Reported Debt (Other Noncurrent Financial Liabilities + Other Current Financial Liabilities) 2021 = 4,322,000,000 + 746,000,000 = 5,068,000,000 EUR
Leases: The facts mention Payments Of Lease Liabilities, but do not provide the lease liability balance on the balance sheet, so we assume 0 for unreported values.
Pension deficit: Not explicitly reported, assume 0.
Eligible Cash: We use Cash And Cash Equivalents 2021 = 964,000,000 EUR (as 2022-01-01 represents the end of fiscal 2021).
Adjusted_Debt (2021) = 5,068,000,000 - 964,000,000 = 4,104,000,000 EUR

Step 5: Calculate 2021 Adjusted_Debt / Adjusted_EBITDA ratio
Ratio (2021) = 4,104,000,000 / 1,428,000,000 = 2.87x

Step 6: Calculate 2021 FFO / Adjusted_Debt ratio
Ratio (2021) = 1,183,000,000 / 4,104,000,000 = 0.288 (28.8%)

Step 7: Estimate 2022 Adjusted_EBITDA
Reported EBITDA (Gross Operating Income) 2022: 1,505,000,000 EUR
Result From Nonrecurring Transactions 2022: 157,000,000 EUR (gain)
Adjusted_EBITDA (2022) = 1,505,000,000 - 157,000,000 = 1,348,000,000 EUR (excluding nonrecurring gains to normalize)

Step 8: Estimate 2022 FFO
Cash Interest (Interest Paid Classified As Operating Activities) 2022: 75,000,000 EUR
Cash Taxes (Income Taxes Paid Refund Classified As Operating Activities) 2022: 201,000,000 EUR
FFO (2022) = 1,348,000,000 - 75,000,000 - 201,000,000 = 1,072,000,000 EUR

Step 9: Estimate 2022 Adjusted_Debt
Reported Debt (Other Noncurrent Financial Liabilities + Other Current Financial Liabilities) 2022 = 5,867,000,000 + 1,022,000,000 = 6,889,000,000 EUR
Eligible Cash (Cash And Cash Equivalents 2023-01-01 for fiscal 2022): 2,584,000,000 EUR
Adjusted_Debt (2022) = 6,889,000,000 - 2,584,000,000 = 4,305,000,000 EUR

Step 10: Calculate 2022 Adjusted_Debt / Adjusted_EBITDA ratio
Ratio (2022) = 4,305,000,000 / 1,348,000,000 = 3.19x

Step 11: Calculate 2022 FFO / Adjusted_Debt ratio
Ratio (2022) = 1,072,000,000 / 4,305,000,000 = 0.249 (24.9%)

Step 12: Classify the year-on-year credit trend
Signal 1 (Leverage): Change in Adjusted_Debt / Adjusted_EBITDA = 3.19x - 2.87x = +0.32x
Threshold: ≥ +0.2x is Deteriorating.
Signal 1 = Deteriorating.

Signal 2 (Cash-flow coverage): Change in FFO / Adjusted_Debt = 0.249 - 0.288 = -0.039
Threshold: ≤ -0.03 is Deteriorating.
Signal 2 = Deteriorating.

Both signals agree on Deteriorating.

<answer>Deteriorating</answer>