Nidalee+RFC and Max Mana at start of round
1.) Hopefully already reported but didn't see it, Nidalee with Rapid Fire Cannon keeps the range from human form when she transforms, allowing her to attack in cougar form from across the map.
2.) If a character has max mana at the start of a round, they instantly use the ability and waste it. Maybe make it so the first ability will only activate after a single auto attack. I've done it on both pyke and akali so far, where they just use the ability and then jump (since they're assassins). Haven't tried it on non assassins yet.