Step 1: Understand the meaning of each sentence.
Both sentences express possibility or fear about something happening in the future.
Step 2: Choose the correct modal.
The modal “might” is used to show a weak possibility or fear. It suits both contexts correctly.
Step 3: Apply the modals.
(a) Sakuni saw that he might be roused again to anger.
(b) He was just afraid that it might happen.
Step 4: Conclusion.
Thus, the modal “might” correctly completes both sentences by expressing possibility and fear.