Rex smiles while looking at the white cocoon in front of him,
The process of Delta evolving is quite flashy and even the descendants are curious about what she will look like after the evolution, it's not an everyday thing to see a mutated animal evolve like this.
Just from the power alone, Delta should reach around early or mid-sixth rank.
While standing on the side, Rex then asks the system as he touches the white cocoon that feels like a solid object even though it's made of mana, 'How long will the evolution takes?'
<Scanning... >
<Approximately a few hours but it might take the whole day>
'What?! The whole day?!', Rex exclaimed inside his head.
One of the reasons he helps Delta evolve is to help him keep the descendants safe, but if it takes all day he will need to protect the descendants on his own.
Especially the fourth rank little girl that is the most likely to die.