The function takes in a string and replaces the second character of the string with another character found by adding 25 to the ASCII value of the original second character.

Now, let's try to code this function ourselves:

[CODE]:
```python
def modified_function(input_string):
    if len(input_string) >= 2:
        new_second_char = chr(ord(input_string[1]) + 25)
        return input_string[0] + new_second_char + input_string[2:]
    else:
        return input_string
```
This code should approximate the behavior of the function provided in './temp/function.py'.