He'll fail and get them all chopped up. Time skip with the parents dead due to not being able to work, and the siblings ragged up in the slums. MC returns with money, flashback to how he barely escaped alone. Despite that, the siblings reject him. The next 20 or so chapters are about MC's struggle to reconcile with the siblings.
What comes after is the best arc, we'll finally be introduced to more bs that I just made up.