Constantine is the adaptation of DC/Vertigo's Hellblazer comic. Thus, if you're used to seeing John on Legends of Tomorrow, you'll find that this version of John deals with those darker topics in far more depth. Here is a general list of things that CAN come up in threading with John, especially if it is in regards to his history or canon.

This list will be updated if the mun feels it's needed to after rewatches of a show she's seen 10+ times.

Possession, occult material, alcohol abuse, drugs, child abuse, child marriages, character death, child death, blood/gore, chain smoking, religious iconography and fictional use thereof, and Constantine is a manipulative bastard