For a 60 year old man who defeated the strongest being in another world, I have to say the MC was a real disappointment. The world-building is also a mess. It feels like the author was just trying to piece together some vague thoughts and gave up halfway.
Seems to me that he told the shadow only to call him that the person's life is on the line, he never met the healer, so there may not be a shadow with the healer, can't blame him for that. Tough luck is all.
feel like OnePunchMan, the main character shows up and defeats any enemies instantly.
All that buildup for nothing. Even Saitama had a few nice fights.
I expected a lot more from a 'monster army general'