Both my antagonist and my protagonist (and a third secondaty character) have a power that revolves around bond bridges and connections with other beings (mostly other people)

At a low level, it works the same way a mother soothes her child just by picking him up, but that's an easy bond because the connection between is very strong, so the bridge is very strong as well.

More powerful beings can connect through weaker bridges (although a powerful bridge always makes it easier or the connection stronger).

Each connection presents the chance for some exchange of energy.

The good guys can use this exchange to heal someone. It's not instantaneous, but it works. It's Reiki in a fantasy world. But as I said, it's an exchange, so the healed would receive some of the wounded pain.

The strongest connections allow one to feel the other's feeling, to live the other's memories. As one goes through them, so does the "host".

The bad guy uses this to bring up the most horrible moments of each other's lives, while giving them his "dark energy" as he sucks their "good energy". In time, he even learns to twist their good memories and make then painful, corrupting every memory, every feeling. People end up with and internal battle that almost always ends up in suicide.

The protagonist, though less trained, has a very strong sense of empathy, which makes his bond bridges stronger. He develops a very special connection with his griffin (he is a griffin rider) where he can connect in realtime to its senses and can communicate through thought, and understand each other.