Thats why i said your suggestion to make it more graceful is a good one for that. But i still think its good if blind spamming isnt promoted on her. And if 4 is too harsh, just reduce the penalty to 3. It allows a lot of tweaking on this part:
- Even if you actualy want to make it 3.5 shots being lost. You can make it grant 2 stacks (where each stack is 0.5) and lose 7 stacks on a miss.
- You could decide that minion kills would also grant a stack (maybe even as talent).
- You could make it reward an additional stack on a W+Q combo.
- You could give her passive stack generation. (for example passively when a minion dies, or just over time)
- You could make it overcharge using basic attacks (each basic attack gives 4 stacks up to 12, upon using snipe it depletes all)
There is a lot of potential of having a dynamic system on her quest that forces her to do alternative tasks to boost it, and these tasks can be made easy enough to perform so that most players will often enough get the boosts anyway.
You could even make talents reduce the snipe aspect:
Just imagine the following change on OitC (The current system effectively remains, but gets these additional effects, which can also get boosted further with other stack related talents):
- Changes the snipe quest to get 10 stacks.
- Each basic ability charges snipe worth 5 stacks
- Each stack grants an additional 10% of AA damage to the next AA shot.
(this allows you to use 2 abilities to get 100% bonus damage)
But if for example at level 13 you get a talent that boosts each stack to double, this would give a AA shot worth 400% damage instead of 200%.
You could also make an ability that gives the player a shield in exchange from being unable to charge and use any stacks for x seconds (heavily affects the bigger quest by nerfing snipe a lot, barely affects this one as the primary damage source is from AA anyway). It could even be made in such way that only the snipe damage is reduced from this (effectively ignoring the AA part entirely).
Its all about potential ideas that can be used and the dynamics that can be created through talents.
And if its truly a problem, you could always make 1 of the talents prevent losing any of the stacks anyway (no additional boosts with it though), and if thats too strong reduce the value per stack to 80% of the regular value.
This allows a static value of damage to be built over time. And by that allow much higher base damage, but due to its delayed damage prevent major hinder during the early game where players might lack counters to stealth, or lack mitigation options.