That might seem redundant, but that also protects it from wither and infect sources of damage, as well as thing the trigger on combat damage to the creature so there is even more going on than at first blush
If you can continue to quest with your Evasives and control the board with Dragon Fire, Mother Knows Best, and Kuzco, you should have an easy time staying ahead on lore
For example, Hexdrinker levels up whenever you pay , and it has three tiers, based on the amount of counters it has
There isn't any good direct comparison to Mangara's abilities, but the closest thing that popped into my head is Runic Armasaur, another creature whose card drawing ability is entirely dependent on your opponents' actions, making the card inconsistent where it sometimes draws you zero cards and sometimes floods you with card draw