"Here I am, standing my ground before the mountains I saw hurl each other seconds before, and you think me a coward?" Tristan asks, amused. "What of this: Her knights seem more afraid of her than loyal - though they are loyal. If you can convince any of [i]them[/i] of your rightness - even one! - before trying to murder Pellinore, then I fight with you tonight. [i]They [/i]are not the ones sworn to Pendragon. If you are to be about the bloody business, anyway, than that is the mercy I can give for the kindness given. Any you convince is one less to fight you, as well, and maybe one to fight alongside you."

This, he thinks, would work. Not on all of them, probably not on most of them. But if Sandsfern and Robena are [i]vanquishing evil[/i], then it would be enough that any close enough to it would recognize evil for what it is. And, he is convinced, it is the only means he has to save any of those knights from the purpose he feels sloughing off Robena in waves. 

He will not be peer-pressured into indiscriminate massacres. Merely discriminate ones. 

He says nothing about Sandsfern's slights against Merlin. He does not want to look a fool for disagreeing purely out of faith, though it's a faith that goes down to the marrow in his bones. He has not yet learned what it is to be disappointed by heroes.