I'm not sure about if one directly targets the symbiote for now, cause if it buffs when it's directly attacked too then that's more evil than immaterial, except the thing dies if you can't get a host.
Though thinking about it, I will say it should prob buff HP and not ATK at all. As a singularity something passes the event horizon and gets sucked in and becomes part of the singularity, adding to it and its HP. I dunno how a singularity would attack.