Impossible?
Sure, because you cant, like, use Dark Magician and a Fusion substitute monster to summon Dark Flare and then you can easily get a Mirage Knight that can body anything and deal 2800 damage at the least.
that combo is not worth it at all though lol. you have to waste deck slots on mirage knight, and mirage knight is only summoned if Dark Flare is destroyed by battle. why would you ever try to use mirage knight as your boss monster when it requires way too much effort to summon for an effect that is not worth it at all. just a complete waste of resources