node, 153 bytes

Result

AC

Duration

2278ms

Code [DL]

s=""+require("fs").readFileSync(0)
console.log(s.replace(RegExp(`\n(.{${s.search(/T/)}}).`,"g"),"\n$1#").replace(/K *#/,m=>`K${"#".repeat(m.length-1)}`))

stdin

           T                                      
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
                                                  
      K                                           

stdout

           T                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
           #                                      
      K#####                                      

stderr

strace