Haha my time to strike! Time to make this sans turn into the LB sans which has like inf phases >:D (Poor sans) (Press space to attack)
You decided to spare him Yet.. Sans wants to forgive you for everything you've done, but his realizes you've destroyed so many AU'S and timelines and if he does not stop you.. you'll destroy more plus his own one so he would die even though you spared him so now his determined to kill you once and for all no matter the cost to end all of the suffering..