If other people were to see what Su Xiaotian is currently doing, they will definitely shout at him for being a mad lad, as attacking ones own nascent source pretty much spells the doom of the cultivator, who will end up in just two states and nothing more, either a cripple or a corpse.
However, the immortal-like young man clearly thinks differently, this attack of him so precise and confident that when his embryonic nascent source is split into two equal pieces, even the nature of his nascent source got separated, one of the sources being extremely bright and flaming hot, the white light coming out of this one so hot that he feels it even in his soul form.
Meanwhile, the other split nascent source feels really dim and cold, the only reason why it is emitting light at all being the fact that it seems to absorb some of the lights of the other embryonic nascent source, the light coming out from it cool and comforting that it makes the immortal-like young man want to fall asleep.