Concepts: Skinlines, fun abilities and utilities.

Skins and skin lines:

Overgrown Skins: Ivern, Moakai, and Zyra. Overgrown would utilize very dark greens with some oranges and purples. Using many different hues of green to bring the kind of life of the forest to these forestry champions.

Deep sea Fizz: Using more dark blues with purples and blacks in the shark. the splash could be more dark turning lighter as it goes out.

Dark worrier skin line: Trynd, Riven, Talon, Leona (kind of a dark eclipse leona), Black plague Twitch. Using a lot of blacks and dark dark purples. Highlighting with certain colors accented for that champion. Like green for riven and purple for talon and orange yellow for leona.

Abilities:

Top laner: AP bruiser kind of champion. one that utilizes space in the lane. Using a teleport to go in and being able to make a wall like anaivia. one that might curve so it requires more skill.

Mid laner: skills that let you make small minions larger. or a gate that lets you gain positive stats other than just speed.

Support: A champion that uses buffs wile targetting friendly units and does damage or stuns enemy targets. Letting you choose to buff or poke. One could give your laner a shield/make an enemy take more damage for a short amount of time. One that speeds up your laner or stuns the enemy laner. A champion that uses totems or banners to do certain things. Like one banner would sheild the team mates around it or one that slows the enemies around it. More of a long distance sona. The banners or totems could last only a little or be killable. There could be a totem around the champion that lets them give and gain movement speed depending on how manny team mates are around. They would be an AP champion with a lot of utility.

ADC: A no mana ADC that uses a heat system or an energy system. Maybe one that is Technological and uses digital attacks.

Jungler: Spawning a creature that you battle. that gives you XP or gold ONLY depending on where you are. Or that can make a teleporter at base so that you can arive at lane or a certain jungle camp instantly. This teleporter can be targeted and killed.