Ahithophel

2 Samuel 15:12
While Absalom was offering the sacrifices, he sent for Ahithophel the Gilonite, David's counselor, to come from his hometown of Giloh. So the conspiracy gained strength, and Absalom's following kept increasing.

2 Samuel 16:23
Now in those days the advice of Ahithophel was like the consultation of the word of God. Such was the regard that both David and Absalom had for Ahithophel's advice.

2 Samuel 17:23
When Ahithophel saw that his advice had not been followed, he saddled his donkey and set out for his house in his hometown. He put his affairs in order and hanged himself. So he died and was buried in his father's tomb.

Hushai

2 Samuel 15:32, 37
When David came to the summit, where he used to worship God, Hushai the Archite was there to meet him with his robe torn and dust on his head. . . .

2 Samuel 16:16
And David's friend Hushai the Archite went to Absalom and said to him, "Long live the king! Long live the king!"

companion

2 Samuel 16:17
"Is this the loyalty you show your friend?" Absalom replied. "Why did you not go with your friend?"

Psalm 55:13
But it is you, a man like myself, my companion and close friend.

Zechariah 13:7
Awake, O sword, against My shepherd, against the man who is My Companion, " declares the LORD of Hosts. "Strike the shepherd, and the sheep will be scattered, and I will turn My hand against the little ones.