I express many Thranduil feels. I express them simultaneously. You may share them. :) Thranduil is my baby, I will cry if you tell me I'm wrong in how I portray him. So pls don't.
Thorin is anger and malice and hatred from years long since passed. He is the regret of a son who could do nothing when his father died. He is the sorrow of a grandson who saw his grandfather dead. He is the hatred of a people left abandoned. He is the malice of a being without hope. And Thranduil sees within him everything that could have been Legolas. Thranduil sees within him everything that once was himself. Thror failed where Oropher failed. Thrain failed where Oropher failed. It would seem now that Thorin would fail there as well. And though Dis would remain at home, trusting and hoping and praying, she would fail there too. Thranduil saw inside of Thorin everything that could have been Legolas, everything that had been Thranduil himself once.
Thranduil did not fail where Oropher failed. Thranduil did not fail where Thrain failed. Thranduil did not fail where Thror failed. Where Dis failed. Where Thorin failed. Thranduil saw within Legolas everything that Thorin could have been. Thranduil saw inside Legolas everything that he had once been himself. Thranduil did not fail where so many had before and after him. Thranduil did not instil within his son anger and malice and hatred so strong they overwhelmed his sense of right and wrong, of necessary and superfluous. Thranduil did not inspire within his son a death wish. Thranduil did not implant within his son a need for revenge so important it was worth the loss of thousands of lives. Thranduil did not stumble his way into danger pursuing a foe he could never defeat. Thranduil did not fail where so many others had and still would.
Thorin stumbles his way off the path and into their midst and Thranduil sees within him everything that Legolas could have and would have been, had Thranduil led his army against the dragon. Fili and Kili die on the battle field and Thranduil sees within them everything that Legolas could have and would have been had Thranduil led his army against the dragon. Thorin stumbles up the mountain side and wakes the dragon, bringing forth his wrath on the innocent, and Thranduil sees within him everything that Thranduil was and would have been had his friends let him fester in his hatred after his father's death. Fili and Kili die on the battlefield and Thranduil sees within them everything that Thranduil was and would have been, had his friends not gripped him tight and pulled him from his father's dead body.
Thorin dies on the battlefield and Thranduil acknowledges that this is how it is and must always be for people like Thorin. That this is how it is and must always be for people like Oropher. That this is how it is and must always be for people like Thrain and Thror, for people who have hatred and malice and anger and no memory of forgiveness and peace. Fili and Kili die on the battlefield and Thranduil acknowledges that this is how it is and must always be for people like them. That this is how it is and must always be for the children led astray by their loved one's misguidance. That this is how it is and must always be for the children led into anger and revenge by their loved one's deaths. That this is how it is and must always be for the children led into darkness by their loved one's mistakes.
Thranduil saw within Thorin all that Legolas could and would have been. Thranduil saw within Fili and Kili all that Legolas could and would have been. Thranduil saw within Thorin everything that he himself had been and would still have been. Thranduil saw within Fili and Kili everything that he himself had been and would still have been. Thranduil looked at Thorin and he knew he had succeeded where so many others had failed. Thranduil looked at Fili and Kili and he knew he had succeeded where so many others had failed.
Thranduil looks at Dis and he cannot begin to imagine her suffering.