Sebastian Vael/Approval

Friendship
Friendship with Sebastian can generally be earned by being helpful to those in need, or siding with the Chantry or templars over the mages.

Act 2


 * A Bitter Pill: if Hawke says, "He is not a slave!"
 * Dissent: if Hawke refuses to help Anders. Dissent:  if Hawke stops Anders from harming Ella. A further  if Hawke then says, "Just what it looked like." upon meeting Ella outside the tunnels, and  if Hawke then tells her to return to the Circle.
 * Family Matter: if Hawke allows Bartrand to live.
 * Fool's Gold: if Hawke tells Emrys that he/she will save Merin.
 * Mirror Image: if Hawke ultimately refuses to give Merrill the Arulin'holm.
 * Offered and Lost: if Hawke says, "Varnell and the others die." Offered and Lost:  if Hawke tells the Viscount not to hide what happened.
 * Prime Suspect: if Hawke begins the conversation with Emeric along an aggressive or humorous line of conversation until Sebastian comments that "this is a worthy cause." and then finishes with the diplomatic option to accept the quest.
 * Questioning Beliefs - Sebastian: if Hawke tells Sebastian to remain a brother in the Chantry, rather than attempt to take back Starkhaven.
 * Repentance: if Hawke says, "Die, fiend." cutting the conversation short when speaking to Allure. Repentance:  if Hawke says, "That's a good point." when speaking to Allure. Repentance:  if Hawke says, "You were all victims." when speaking to Flora at the end of the quest. Repentance:  if Hawke uses the following options upon returning to the Chantry:
 * "That's a good question."
 * "What do you want to do?"
 * "Listen to your heart."

Act 3


 * On the Loose: When you talk to Meredith, if you're willing to help the templars.
 * Alone: if Hawke convinces Fenris to allow Varania to live.
 * Faith: When accepting the quest you can earn up to . When asked to meet with Nightengale, reply "Of course" for .  Then choose "We'll go right now." for an additional . Faith:  if Hawke tells Sister Nightingale that the situation in Kirkwall is not as bad as it seems. Faith:  In the final conversation when the Grand Cleric refuses to leave, reply "Please Reconsider" for  or "That's Morbid" for.
 * Haunted: After the battle, give the idol piece to Sandal to craft a rune with for.
 * Finding Nathaniel: In the Deep Roads, when you talk to Nathaniel Howe, Sebastian will express approval of 'rescuing a warden in peril'..

Rivalry
Rivalry with Sebastian can generally be earned by siding against the Chantry or by making aggressive, disagreeable or otherwise "dishonorable" choices.

Act 2


 * Talk to Grand Cleric Elthina with Sebastian in the party, choose "You're useless".


 * A Bitter Pill: During the first ambush, offer to make a deal.
 * Blackpowder Courtesy: Killing the dwarf Javaris
 * Dissent: Agree to help Anders (using the witty path) Dissent: Agree to help Anders (using the aggressive path)  Dissent: Let Anders kill Ella
 * Family Matter: Have Varric kill Bartrand
 * Fool's Gold: Telling Emrys that you'd rather have the weapon than save his brother
 * Mirror Image: Give Merrill the arulin'holm
 * Night Terrors: Accept the quest from Arianni (note: approval will only count if small cutscene of Sebastian disapproving of the quest is shown, and sometimes it is not shown, depending on which characters you have in the party)
 * NOTE* I got this when I had Anders and Merrill in my party, along with Sebastian.
 * Night Terrors: Tell Marethari that you will not kill Feynriel
 * Offered and Lost: Tell Ser Varnell to kill the Qunari
 * Prime Suspect: Picking all the aggresive responses when talking to Emeric
 * Questioning Beliefs: When speaking to Sebastian, the first and second set of choices all take you the same place. In the third set, if you choose Starkhaven you will give, (If you maxed friendship, he will not gain rival approval)
 * Repentance: When speaking to Allure, choose "Don't listen to her"
 * Repentance: When speaking to Flora, choose "Don't try to wiggle out of this"
 * Repentance: During the Final conversation back in the chantry, choose "You must take back your land."
 * Starkhaven Longbow: Respond "Use it to avenge them."

Act 3


 * Alone: Let Fenris kill Varania.
 * A Murder of Crows: Sleep with the assassin when given the chance right at the end of the quest.
 * A New Path: In the beginning of the quest if you force Merrill to talk to Marethari without asking by just talking to Marethari before hand, and you pick the option to ask Marethari to help fix the eluvian you will earn.
 * Faith: In the final conversation when the Grand Cleric refuses to leave, reply "Fine, your choice" Faith:  In the conversation with Sister Nightingale, tell her it's time for a holy war.
 * Haunted: Let Varric keep the shard of the Idol at then end of the quest gives
 * No Rest for the Wicked: During the final conversation with Castillon, allow Isabella to trade the incriminating documents for Castillon's ship.
 * On the Loose: During the conversation with Walter reply aggressively to gain and an extra  if later when you speak to him you refuse to give Walter and Cricket money.
 * On the Loose: Allowing Emile to go free results in another

Legacy DLC
 * Altar of Dumat: Offer a tribute to Dumat.
 * Side with Larius instead of Janeka.