first off: want to say i love the idea
second: here's my take on what Avery could be. Really like your idea; inspired to create my own
Avery uses a unique resource - fuel. Its cap is set at 100; an important feature of fuel is that it regenerates quickly while Avery has not basic attacked or used an ability in the last 2 seconds and very slowly if she has; another is that Avery lacks any options in combat for effectively regenerating this resource. this gives Avery a window of opportunity at the beginning of a teamfight or hard engage for high amounts of area damage that steeply tapers off as the battle progresses, forcing her to choose between staying to attempt to finish off the remaining enemies at a serious personal disadvantage, or disengaging to regain fuel. Alternatively, by using the resource extremely prudently during fights, she can direct surgical applications of meltiness on high value targets and save the bulk of her fuel to clear out any stragglers. Grenade !!!! is not a reliable or instantaneous source of hard cc, and so if jumped upon unprepared Avery may be forced to blow her ult, and in doing so, a great deal of her fuel reserves.
Passive: Down to Ashes
every fourth successive attack (reset after 2 seconds without basic attacking) is a channel that hits enemies in a long, narrow cone three times at an increased rate (these attacks count towards the next proc; a full channel will put the counter at 2 attacks towards the next proc). Onhits including lifesteal are calculated only on the primary target; all enemies hit will suffer from any critical strikes and from Gasoline procs. Issuing a move command breaks the channel early and resets the attack counter.
Q: Overburn | 5 fuel per attack initially, increased by 5 fuel with each successive attack | 12-4 sec cd | toggled
while active, Avery expends fuel with each attack to increase AD (increased with every basic attack while active). The longer the ability is active, the greater the cost and damage increase. She also gains a flat attack speed boost while the buff is active.
W: Grenade !!!! | no cost | 15-11 sec cd | fire and forget
Avery tosses a grenade which explodes after a set time. The grenade will always bounce twice before coming to a resting position. bounce distance is dependent upon the distance traveled during the previous bounce. Each time the grenade makes contact with the ground, surrounding units (allies and enemies alike) gain a brief movement speed boost, with allies gaining a larger boost than enemies. If Avery is within the radius, she is also cleansed of slows and CC. When the grenade detonates, it deals high magic damage and stuns enemies in its radius for a moderate duration.
E: Road to Ruin | 10 fuel per .75 seconds | 5 sec CD | toggled
Avery expends fuel to lay down a line of sticky, highly flammable gasoline which slows enemies while in it (think Ah Muzen Cab from Smite) and applies a debuff that increases the damage of Avery's basic attacks against them, stacking once per second up to 5 times and removing one stack per basic attack. The trail itself can be ignited by any of avery's attacks or abilities, dealing %hp magic damage per second to those within with an AP scaling ratio.
R: Scorched Earth | 50 fuel | 120/90/60 sec cd | brief delay
In a cataclysmic blast, Avery burns down the terrain in a huge radius around her to nothing for 10 seconds, dealing initial magic damage increased by an AP ratio and preventing healing or health regen of any kind on anyone within. Any enemies tagged with Gasoline who are hit by the initial blast are stunned and take bonus damage and the debuff is removed.
I think the most notable features of this kit are as followed:
Avery lacks a dash or instant repositioning tool, but has a wealth of tools at her disposal for aiding a well-planned ambush or protecting herself from a known threat such as a teleport from toplane or an imminent tower dive. her lack of on-demand burst and the set-up nature of much of her damage can lead her to have trouble against enemies such as graves, lucian, or pretty much any fed assassin in the game, but the combination of her passive, Overburn and Road to Ruin will allow her to melt down other threats in short order. Avery is at her best in teamfights, when her CC, healing removal, and disgusting amounts of area dps begin to shine. Fuel provides a unique opportunity for Avery to allocate her resources effectively (or ineffectively) depending upon the situation presented, giving her the wherewithal to choose between a defensive, middle-distance strategy, single target melterino, or a brief fiery holocaust upon the entire enemy team.
