There are some places you can change, but if you wish to see Qualian dead, it is not recommended to change the final result afterwards. This also applies to some events in the orphanage.
Also: resurrecting a quest NPC will not work because the running scripts and IDs will be changed.
So if Thárael is dead, he can't be revived for quest.
No, I don't wish to see Qalian dead, I just didn't try to stop Tharaêl from doing it. But if changing it would help bring Tharaêl back, that's okay. The rest of the right conditions for a good ending have been done, but this moment... damn. I see on the internet that this could have been changed
before the last dialogue with him in the "Dark Chambers of our Mind" quest, but it's too late for me...
So if he can't be revived, can I just restart his quests so I can complete it normally? I saw the console command "resetquest questid", can it help me?
Of course you could bring a new Tharael into the house via mod, but that might not be what you want.
Hmm, which mod are you referring to?