changing value inside for loop which also is a criteria for the looping

Maybe like this?

Sub AddRowsBetween()
    Dim i As Long: i = 1
    Dim j As Long
 
    Do Until Cells(i, 1) = ""
        For j = 1 To 10
            Cells(i + j, 1).EntireRow.Insert
            Cells(i + j, 1).Value = j
        Next j
        i = i + j
    Loop
End Sub

BSB