Champion Concept - Dusk
Support, mage. Passive While moving dusk leaves a shadow trail that can be manipulated by his abilities(decays after 4 seconds). Q - Creeping shadow Converts and Pushes the current trail as a pass-through skill-shot dealing magic damage to enemies it passes through.
W - Shadow crystals Converts the trail into terrain for a duration, that knocks up any enemies in range dealing magic damage. (Can still be pushed while up).
E - Absent light Dusk and allies that enter the trail are granted invisibility and additional movement speed for a small duration. R - Eclipse Dusk plunges the entire map into darkness (putting the trail EVERYWHERE). This limits all enemy visibility. (since the whole map is covered in shadow trail, the basic abilities can still be used at infinite range).