The End of Suffering is Norio Tale 7 of 9 and the last of his Act 2 tales, where you protect Kushi Temple's monks from another Mongol attack. It rewards the Charm of Fortitude and the Clear Summer Headband.
Part 7 of 9 in Norio's Tales
Part 24 of 66 in Tales of Tsushima
The Mongols are about to hit Kushi Temple again, this time to punish it for resisting. Norio stays to defend the temple while you go after the monks outside its walls. Kill the messenger first. Reach the monks by the river, talk to them and fight off the Mongols there. Then escort them back to the temple, beating another group on the way, and regroup with Norio.
Talk to Norio. Kill the Mongol messenger. Reach the monks at the river and talk to them. Beat the Mongols and talk to Norio. Escort the monks back, beating another group. Talk to Norio and go with him.
The temple holds, though the Buddha statue you recovered is destroyed in the fighting. Seeing Jin and Norio stand firm, the Kushi monks finally agree to join the fight against the Mongols.
The Birth of Suffering
The Birth of Suffering is Norio Tale 4 of 9, a short Act 2 side tale where you arrive at Kushi Temple to find it under Mongol attack. It is one straight fight alongside Norio and the temple monks, and it only rewards a minor Legend increase.
The Blood Sutra
The Blood Sutra is Norio Tale 5 of 9, an Act 2 side tale where you search for Kushi Temple's missing abbot. The trail runs from Koshimizu Farmstead to a waterfall. It rewards the Charm of Resistance II and 2 Silk.
The Cause of Suffering
The Cause of Suffering is Norio Tale 6 of 9, an Act 2 side tale where you recover Kushi Temple's stolen Buddha statue from a Mongol camp. It starts at Kushi Temple and rewards the Charm of Well Being II and 2 Silk.
Ghosts in the Fog
Ghosts in the Fog is Norio Tale 3 of 9, an Act 2 side tale where you defend Akashima Village from a Mongol counterattack using incense burners as traps. It rewards the Charm of Unyielding II, the Noble Fighter's headband and 2 Silk.