Cells are pretty powerful. Remember there are organisms with dozens of times the genetic code size of humans. So a lot can be coded in the genome.

An asi can design multicellular machinery that is unevolvable and immune to all known existing pathogens. While being able to breakdown all known biological life and human infrastructure. The cellular machinery can interact with inorganic computing substrate that controls and guides it. It can have energy harvesters and resource harvesters that keep the replication machinery churning at peak efficiency.

It could produce carbon nanostructured military equipment controlled by asi in large amounts, quickly exceeding all known militaries combined.

It would be the ultimate lifeform. The merging of information technology with biology.