**spoiler**
sasuke asks hashirama what a shinobi is
hashirama pauses for a moment and has a flashback to his fight with madara
hashirama tells madara that he understands his pain, but the meaning of a shinobi is to endure pain
madara tells hashirama to stop lecturing him like hes an academy student. that his teaching of a shinobi is wrong
we get to see some fighting between hashirama and madara