Just confirmed on the forums by the developer Batuba, these three legends got fixed internally. Both Shazam & Bane use a supercharge that heals them, and Donna Troy has a healing power.
According to these threads:
Donna Troy -
https://forums.daybreakgames.com/dcuo/index.php?threads/legends-donna-troys-healing-power-does-not-work.304332/#post-4263613
Shazam -
https://forums.daybreakgames.com/dcuo/index.php?threads/legends-shazams-heal-power-doesnt-work.304330/#post-4263614
Bane -
https://forums.daybreakgames.com/dcuo/index.php?threads/legends-banes-supercharg-is-bugged-not-healing.304323/#post-4263612
All three got fixed internally!
To us it looks like the start of many changes to come to Legends PvP and PvE, and we're very excited to see what's coming next. Because Legends like Atrocious and Saint Walker, still need to fix their Supercharges.