**Step 1: Identify the relevant industry**
VERBUND AG is Austria's leading electricity company and one of the largest producers of hydroelectric power in Europe. Based on the provided industry methodologies, its primary operations involve electricity generation and grid operations. While it has regulated grid revenue, a substantial portion of its business (particularly electricity sales) operates in unregulated markets. Given the mix of regulated and unregulated power operations, the methodologies for "Regulated Utilities" and "Unregulated Power And Gas" are relevant. No specific ratio adjustments for debt or EBITDA differ drastically between these two for this basic calculation, so we proceed with the baseline formulas using the provided financial data.

**Step 2: Estimate 2021 Adjusted_EBITDA**
Formula: Adjusted_EBITDA = EBITDA (reported) + adjustment_leases + nonrecurring_losses - nonrecurring_gains ± pension_adjustments ± joint_venture_proportional_EBITDA ± other_normalization_adjustments
For 2021:
- Reported EBITDA (2021): 1,578,959,000 EUR
- Leases: We add an estimate for lease interest and depreciation. For 2021, right-of-use assets depreciated are implied in D&A, and lease interest is part of finance costs. We use the standard S&P adjustment of 8x rent (interest = 1/3, dep = 2/3). Rent expense can be estimated from the repayment of lease liabilities (27,523,000 EUR) and interest portion. A simpler standard proxy is 8x the lease liability repayment. 8 * 27,523,000 = 220,184,000 EUR.
- Nonrecurring/Impairments: Add back Impairment Loss (9,869,000 EUR) and subtract Reversal of Impairment Loss (115,009,000 EUR). Net impact = -105,140,000 EUR.
- Pension adjustments/JV/Other: Assumed immaterial/netted out for this level of estimation without specific actuarial data.
Adjusted_EBITDA 2021 = 1,578,959,000 + 220,184,000 - 105,140,000 = 1,694,003,000 EUR.

**Step 3: Estimate 2021 FFO**
Formula: FFO = Adjusted_EBITDA - cash_interest - cash_taxes
- Adjusted_EBITDA 2021: 1,694,003,000 EUR
- Cash Interest 2021: Interest paid (17,900,000 EUR) + Lease interest paid (estimated as 1/3 of lease adjustment: 220,184,000 / 8 = 27,523,000 EUR / 3 ≈ 9,174,333 EUR). Total Cash Interest ≈ 27,074,333 EUR.
- Cash Taxes 2021: Income Taxes Paid = 238,200,000 EUR.
FFO 2021 = 1,694,003,000 - 27,074,333 - 238,200,000 = 1,428,728,667 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 2021: Noncurrent Financial Liabilities (1,202,154,000 EUR) + Current Financial Liabilities (84,056,000 EUR) = 1,286,210,000 EUR.
- Leases 2021: Right-of-use assets reported = 110,663,000 EUR. (We'll use the ROU asset as the debt proxy for operating leases, a common S&P method).
- Other debt-like items: None explicitly material.
- Eligible Cash 2021: Cash and Cash Equivalents = 49,203,000 EUR.
Adjusted_Debt 2021 = 1,286,210,000 + 110,663,000 - 49,203,000 = 1,347,670,000 EUR.

**Step 5: Calculate 2021 Adjusted_Debt / Adjusted_EBITDA**
Ratio 2021 = 1,347,670,000 / 1,694,003,000 = 0.80x

**Step 6: Calculate 2021 FFO / Adjusted_Debt**
Ratio 2021 = 1,428,728,667 / 1,347,670,000 = 1.06 (106.0%)

**Step 7: Estimate 2022 Adjusted_EBITDA**
For 2022:
- Reported EBITDA 2022: 3,160,679,000 EUR
- Leases adjustment: 8 * Lease liability repayment (11,447,000 EUR) = 91,576,000 EUR.
- Nonrecurring/Impairments: Add back Impairment Loss (197,761,000 EUR) and subtract Reversal of Impairment Loss (125,973,000 EUR). Net impact = +71,788,000 EUR.
Adjusted_EBITDA 2022 = 3,160,679,000 + 91,576,000 + 71,788,000 = 3,324,043,000 EUR.

**Step 8: Estimate 2022 FFO**
- Adjusted_EBITDA 2022: 3,324,043,000 EUR
- Cash Interest 2022: Interest paid (36,100,000 EUR) + Lease interest paid (91,576,000 / 8 / 3 ≈ 3,815,667 EUR). Total Cash Interest ≈ 39,915,667 EUR.
- Cash Taxes 2022: Income Taxes Paid = 343,100,000 EUR.
FFO 2022 = 3,324,043,000 - 39,915,667 - 343,100,000 = 2,941,027,333 EUR.

**Step 9: Estimate 2022 Adjusted_Debt**
- Reported Debt 2022: Noncurrent Financial Liabilities (1,834,155,000 EUR) + Current Financial Liabilities (1,462,453,000 EUR) = 3,296,608,000 EUR.
- Leases 2022: Right-of-use assets reported = 103,826,000 EUR.
- Eligible Cash 2022: Cash and Cash Equivalents = 318,562,000 EUR.
Adjusted_Debt 2022 = 3,296,608,000 + 103,826,000 - 318,562,000 = 3,081,872,000 EUR.

**Step 10: Calculate 2022 Adjusted_Debt / Adjusted_EBITDA**
Ratio 2022 = 3,081,872,000 / 3,324,043,000 = 0.93x

**Step 11: Calculate 2022 FFO / Adjusted_Debt**
Ratio 2022 = 2,941,027,333 / 3,081,872,000 = 0.95 (95.4%)

**Step 12: Classify the year-on-year credit trend**
- Signal 1 (Leverage): Change in Adjusted_Debt / Adjusted_EBITDA = 0.93x - 0.80x = +0.13x. 
  Threshold: ≥ +0.2x is Deteriorating. +0.13x is between -0.2x and +0.2x, so this signal is **Stable**.
- Signal 2 (Cash-flow coverage): Change in FFO / Adjusted_Debt = 0.954 - 1.060 = -0.106 (or -10.6 percentage points).
  Threshold: ≤ -0.03 is Deteriorating. -0.106 is significantly below -0.03, so this signal is **Deteriorating**.
  
Combining the signals: Signal 1 is Stable, Signal 2 is Deteriorating. Following the rule ("If one is Stable and the other is Improving or Deteriorating, return the non-Stable category"), the credit trend is Deteriorating.

<answer>Deteriorating</answer>