Sure, I can help you write a test case generator for the "Ennichi" problem. The generator will create random test cases based on the problem constraints. 

Here's the test case generator in Python:

```python
import random
import string

def tcgen():
    # Generate random values for h, w, and n
    h = random.randint(2, 30)
    w = random.randint(2, 30)
    n = random.randint(2, 30)
    
    # Generate the field with h rows and w columns
    field = []
    for _ in range(h):
        row = ''.join(random.choice(string.ascii_uppercase + '.') for _ in range(w))
        field.append(row)
    
    # Ensure the field contains at least one block
    if all(row.count('.') == w for row in field):
        random_row = random.randint(0, h - 1)
        random_col = random.randint(0, w - 1)
        field[random_row] = field[random_row][:random_col] + random.choice(string.ascii_uppercase) + field[random_row][random_col + 1:]
    
    # Ensure no initial alignment of n or more blocks of the same color
    for i in range(h):
        for j in range(w):
            if field[i][j] != '.':
                # Check horizontal alignment
                if j + n <= w:
                    block = field[i][j]
                    if all(field[i][j + k] == block for k in range(n)):
                        # Invalidate the sequence
                        for k in range(n):
                            field[i] = field[i][:j + k] + '.' + field[i][j + k + 1:]
                
                # Check vertical alignment
                if i + n <= h:
                    block = field[i][j]
                    if all(field[i + k][j] == block for k in range(n)):
                        # Invalidate the sequence
                        for k in range(n):
                            field[i + k] = field[i + k][:j] + '.' + field[i + k][j + 1:]
    
    return h, w, n, field

# Example usage of the test case generator
h, w, n, field = tcgen()
print(f"{h} {w} {n}")
for row in field:
    print(row)
```

### Explanation

1. **Parameter Generation**:
    - Random values for `h`, `w`, and `n` are generated within the given constraints.

2. **Field Creation**:
    - Each row of the field is generated randomly with uppercase letters and periods.
    - Ensure there is at least one block (not all periods).

3. **Alignment Check**:
    - The generator checks for horizontal and vertical alignments of `n` or more blocks and adjusts them to prevent initial alignments.

4. **Output**:
    - The function returns the values of `h`, `w`, `n`, and the generated field as a list of strings.

You can use this generator to create varied and extensive test cases to thoroughly test the solution for the "Ennichi" problem.