Maybe she hasn't thought about it at all. Or she'd rather not risk them getting strong again, infused by goddess mind control and repeat the seal again. Im more concerned about the hero being adamant in saving the dragon, as its clearly one of the dragons Lufasu (and the world) need gone so ot cant help wipe the worldIf the elixir can cure the disabilities of the remaining 3 heroes then why the hell hasn't the mc thought of using them? It would be helpful if she could get those 3 as backup and make sure that she won't have to keep interfering every time they have a problem they can't handle themselves.