The words trilogic and trilogical exist, but they are very rare and unidiomatic, and you would do well to avoid them. Offhand I can't think of any circumstance where you could not use the noun trilogy rather than a phrase such as trilogic work.
The adjective form of trilogy is "trilogical."
lord of the rings trilogy was truly amazing. It is truly out of this world.
A trilogy.
The plural of trilogy is trilogies.
it is the prequel of the trilogy
There are three movies in a trilogy.
The Darkangel Trilogy was created in 1982.
The Bounty Trilogy was created in 1936.
The Wimbledon Trilogy was created in 1993.
Gorse Trilogy was created in 1953.
Cairo Trilogy was created in 1956.
Larklight trilogy was created in 2006.
The Beaver Trilogy was created in 2001.