Suggest in order to

[Xinfu]

Could I use to be?

-TS Eliot was looking at the dark moon that was suggested __ the Moon of Death.

If suggest=advise, I would say no, but the sentence above seems to show it to have a different meaning.

[MWoll]

The sentence seems odd to me.

TS Eliot was looking at the dark moon, which seemed to be the Moon of Death. (It's like the Moon of Death.)
TS Eliot was looking at the dark moon, which suggested the Moon of Death. (It made him think of the Moon of Death.)

I don't like the "that".

For me: "He looked at the car that was blue." -- the blueness of the car is vital here, important.
"He looked at the car, which was blue." -- the blueness is incidental, the car happens to be blue.

[Rusty]

If someone had suggested that the dark moon was the Moon of Death, and TS Eliot started to look at it, the sentence is fine with 'to be' in it.

[Xinfu]

Excellent answer. Thank you.