Last!Tale

Well i was thinking and i got good idea for a new AU
Here it is
Plot : It all was like normal Undertale, However the 8th human, Frisk went on a genocide route and was ultimately stopped by sans in the judgement hall. Sans injected himself with determination to help against the battle and a tough battle approached but Frisk eventually died from sans and could not reset. However sans could not absorb frisk's Soul either as for 1. He already had a amount of determination , any more would kill him probably 2. He attacked with such determination that the humans soul shattered. Well after that Sans , Asgore and flowey were the last remaining. Asgore realizing that everyone is dead He decided to preserve his soul if another human ever came Asgore wanted them to be able to escape "this cursed place" So he killed himself and preserved his soul. Flowey went on his own journey and occasionaly annoyed Sans. and Sans well just didnt know what to do so he resided in the ruins waiting for the next human
Story :The 9th human falls down and Sans takes care of them instead of Toriel due to the fact that shes dead, Flowey does also come a while to annoy the human but does not try to kill him and instead trys to train him because he respects Sans. Sans also taught the human about the feature of the save, Even demonstrating it by killing the human when they had just saved. Sans can also remember timelines now due to the determination he was injected with. Along the whole journey to Asgore's soul Sans is with you. Note: (Even though sans does battle you when you try to leave the ruins like Toriel it is useless to try fight Sans as his increased determination allows him to dodge forever, You need to convince him to let you leave.) . Also a genocide route is not possible due to the fact that all the monsters are already dead. The endings are Neutral ending where you take Asgore's soul and leave the underground. True Pacifist ending : Where flowey absorbs the six human souls and Sans soul Note: this is possible only when you convince sans to take up the whole journey even throughout the Asgores house, otherwise Flowey will not appear to try absorb the six souls alone. After Asriel's battle because Sans soul with determination is equivalant to 1 human soul. He destroys the barrier and the remaining Survivors which means the human, Sans and Asriel ( soon to turn into flowey) manage to finally escape the underground.
Note : please dont remove this au if it is not meeting standards please tell me what to do and ill fix it, just please dont remove.