Saw this yesterday and got to thinking about it. Some I left blank because I ran out of ideas. Each design I tried to make as unique as possible trying to avoid being a copy & paste of existing champions. All in all, it'd be better to just develop 5 different unique play styles that change depending on the item purchased. This would be much easier as opposed to designing a 1 ability fits all scenario.
Passive: Shopaholic
At the start of the game you can purchase a unique weapon from the shop. You can only purchase 1 unique weapon per game. Abilities become unlocked after purchasing a unique weapon. Upgrade is unlocked on abilities after purchasing the upgraded version of each unique weapon.
Skirmisher
MK III Tactical Hex-Core Suit- HP restore on hit, +AD, cost 450G
MK V Tactical Hex-Core Suit- Lifesteal, +Atk Spd, +AD, MK III + XG
Resource: Heat
Q- Dash in a targeted direction.
Upgrade: Damaging units reduces the cool down of this ability.
W- Your next auto attack is amplified becoming 450 ranged and causes you to attack 3 times in quick succession. This ability consumes heat and has no cool down.
Upgrade: You gain bonus AD during the duration of this ability.
E- Lock onto your target marking them. While marked for the first 5 seconds that target is revealed by true sight. Whenever you damage a marked target they take bonus damage; however, this effect cannot be applied more than once every few seconds. If your target is no longer in range or is changed the effects of this ability end.
Upgrade: Damaging marked targets reduce their armor.
R- Continuously generate heat for a short duration increasing your movement speed. After this ability ends you must cool down and cannot cast abilities for a short duration.
Upgrade: Basic attacks burn your target for magic damage over time while you are cooling down.
Juggernaut
Old type Hex-Core Combat Suit- Increases base HP, +AD, bonus damage to minions, cost 450G
Neotype Hex-Core Combat Suit- Increases base HP, +AD, +CDR, bonus damage to champions, Old + XG
Resource: Heat
Q- Perform a lariat striking all enemies and knocking them backwards while moving in targeted direction slightly.
Upgrade: This ability has 2 charges.
W- Leap a short distance to strike the ground below you damaging and slowing all units struck. You are briefly slowed when using this ability.
Upgrade: Apply knock-up to units struck.
E-
R- Active: For a short duration a portion of your auto attack damage is converted to true damage. After this ability ends you must cool down and cannot cast abilities for a short duration.
Passive: You regenerate health when you lose heat.
Upgrade: You are granted Heat on hit when this ability is activated.
Tank
Prototype Hex-Core Morph Suit- Increases base HP, +Armor, +Magic Res, cost 450G
Neo Hex-core Augment Suit- Increases base HP, +Armor, +Magic Res, +Tenacity, +Move Spd, Proto + XG
Resource: Heat
Q-
Upgrade:
W- Active: Consume Heat to unleash a wave of energy dealing magic damage equal to your bonus armor and magic resistance.
Passive: Lose armor and magic resistance while this ability is on cool down.
Upgrade: Gain increased movement speed while this ability is on cool down.
E- Active:
Passive: Taking damage grants Heat.
Upgrade:
R-
Utility Mage
Hex-Tuner- Increases MP regen, +AP, +CDR, cost 450G
Augmented Hex-Transmuter- Increases MP regen, +AP +CDR, Hex-Tuner + XG
Resource: Mana
Q- Fires in a line stopping at the first target hit. Upon hitting a target the projectile explodes dealing damage in a cone to all targets.
Upgrade: Hitting an enemy champion will restore a percentage of your missing mana.
W- Send out a wave of energy in a large radius. Enemy champions struck by this wave become marked and are revealed for a short duration. Marked champions take bonus magic damage from you and your allies consuming their mark.
Upgrade: The cool down of this ability is refreshed when you cast another ability.
E- Damage all enemy units within a radius. Enemy units damaged by this ability have their magic resistance reduced stacking up to a maximum.
Upgrade: The cool down of this ability is reduced by 50% when you damage a marked target with this ability.
R- Whenever you cast a spell a portion of that mana cost is stored into this ability up to a maximum. Deal magic damage in an area equal to the amount of mana stored by this ability.
Upgrade: Your abilities deal bonus magic damage equal to a percentage of your maximum mana.
Burst Mage
Hex-Amplifier- Increases MP regen, +AP, bonus damage to minions, cost 500g
Unstable Hex-Oscillator- Increases MP regen, +AP, bonus damage to champions, +CDR, Hex-Amp + XG
Resource: Mana
Q- Mark a target dealing magic damage to them while moving away from them slightly.
Upgrade: Damaging a marked target grants you bonus AP for a short duration.
W- After a brief delay magic strikes down onto your current location dealing magic damage in an area. After the initial strike magic damage is dealt to units around you every few seconds for a short duration.
Upgrade: Targets damaged by this effect have their magic resistance lowered.
E- Dash in targeted direction dealing magic damage to all enemies struck.
Upgrade: Targets struck by this dash are silenced.
R- Launch a sphere of magic in a targeted direction pushing yourself back. Deals magic damage 3 times to area.
Upgrade: Attacks 5 times instead of 3.