it's cultivation novel, little sister has lukemia, mc has system cheat where he uses money to improve skills i think the first thing he used it on was some pill and the starting cultivation technique there is also schools and the mc is going to sit for the exams at the start later on he goes to uni i think i don't really remember but i think the mc name is su mu or something like that
I just remembered a joke about gundam iron blooded orphans, the name in japanese then translated by google is leukemia orphans
Poor op thinkinh someone is answering his question only to find people derailing from the topic to ibo
Do you remember if it was on NU, RRL, or Scribblehub? That could help narrow it down. Not sure if it is Versatile Mage, but I remember one where the MC has lightning and fire powers. He had a cheat necklace(?) but no system.