Complex sentence: The Mark of Death is slowly eating him, but he keeps this a secret from Mikan.Mikan later find out and tries to suck out the piosen with her stealing alice.Nurumi slaps er telling Mikan not to do it, but Mikan does it anyway.
Split into simpler sentences: The Mark of Death is slowly eating him, but he keeps this a secret from Mikan.Mikan later find out and tries to suck out the poison with her stealing alice. Narumi slaps her telling Mikan not to do it, but Mikan does it anyway.