Got a few here and there:
Q: Nasus has the ability to drain the essence of those he slays, empowering him in the process. Given his currently weakened state in the lore with his strength and powers having atrophied over the eons of wandering, I like to entertain the idea that he'll be looking to empower himself in this way, as a bid to mathc the strength of Renekton's fury and Xerath's monsterous magic.
Fizz's trident is made of seastone, and as such is imbued with a great amount of water based magic. While his trident is already deadly to beings of flesh and blood the magical component allows it to counteract magical defenses, rending foes that would normally be unaffected by physical arms. I like to imagine Fizz could probably do some harm to beings from the Shadow Isles just because of his trident.
All of Trundle's abilities stem from him being a Frost Troll with a magical medium; while humans simply use their weapons, Trundle can manipulate ice thanks to Boneshiver because his kind have evolved over time in the Freljord, for much longer than humans, and as such are imbued with a natural proficiency for ice magic. They just need a bit of a hand in learning how to wield it, or the proper tool to open up these latent powers.
These champions are among a tiny group of beings found on Runeterra with true healing magic.
Bard, Taric and Soraka's healing powers are the most alien to Runeterra but also the most potent, while also requiring that they must spend a portion of their own celestial energies to use this power. Soraka's disconnection from the stars means she has to sacrifice her own lifeforce to heal, The Protector does the sacrificing for Taric, but given the nature of Aspects this isn't as hard for it as it is for Soraka, while Bard only expends a small amount of power to create his shrines that slowly gathers in strength as time goes on, allowing him to impart healing to a greater amount of people over an extended period of time. This kind of healing can heal fatal wounds, cleanse illness, and could purify corruption such as the Black Mist.
Janna, Nami and Sona's healing is not as potent as celestial healing, but it's much easier for them to use and apply to others. Nami can give a good burst of healing with her waters while Janna and Sona need a more concentrated effort. While not as powerful this kind of healing is also capable of fixing wounds, cleansing illnesses and potential purifying corruption, just not as easily.