Why isnt the MC, merging his bone marrow, so that he can have much better blood ? Or why isnt he merging daily few cells per some distance, the system could help him do it, right ?
ok...mc fuses eggs in front of his brother then worries about telling him he can fuse things like armor....does author not read his own words? he could just play it off as a special spell instead of system. trying to hide something you showed off like a magic trick makes no sense.