in the garden and the ocean, each time the golden reapers kill an object a new thing appears in there, either to expand or to add something new like the red skull cushions, or the hydra in this case

yea but thats a name made up for it by the director so nameless killed him because he said it aloud

the other time id assume it was because it was an illusion of the director speaking to reaper

its easy for you to say since we know he is suspicious due to us knowing more than sunny, for example the fact mordret is chained in a seven sided room with mirrors all around him, even the fact he was happy that sunny escaped, this all makes him suspicious

sunny did not know that the mirror allowed mordret to see everything he was doing since he had a lack of information so its reasonable for him to be tricked