The legendary Slug Sannin, Tsunade. Or, the Legendary Sucker. A powerful kunoichi able to punch so hard that mountains crumble around it. Her healing ability and skills are so potent that she could bring people from the brink of death.
You gain the legendary Strength of a Hundred Seal, as well as perfect Chakra control.
On top of that, you can summon a massive slug that can be used as a proxy for your powers. This slug can turn into thousands of smaller slugs, able to cover and protect an entire village of people and heal them.