Infinity Edge Balance Change Idea
I have been noticing that Infinity Edge is a little good of an item on its own and Infinity Edge marksmen are being a little too bursty, creating a ranged assassin with sustain damage. So this is not so much about nerfing marksmen damage, but delaying their damage so they are re-focused as sustain damage dealers and require bombarding their attacks on a focused target.
IDEA:
Infinity Edge: Recipe: B.F. Sword (1300g) + Pickaxe (875g) + Cloak of Agility (800g) + 625g = 3600g [+200g more, the item is a multiplier like Rabadon's Deathcap, so it should be the same or greater price than it considering it is the same more powerful than deathcap.]
Statistics: +70 Attack Damage +20% Critical Strike Chance +UNIQUE Passive: Every 3rd basic attack against the same target deals 0%(+100% per 100% Critical Strike Chance) increased damage.
So what this does is makes the big damage delayed and since 100% or very high crit chance is a lot easier to obtain allows for the big damage to always happen a second or two after the first attack. This mechanic also tones back on RFC and Shiv's burst as well since the bonus damage is a proc effect instead, offers more gameplay to the item's damage. The damage increases all of your basic attack's attack damage, so multiplies with critical strikes.
An example comparison at 100% crit chance between this version and current Infinity Edge: 250+250+250 vs 200+200+400
So the damage ends up being 750% vs 800% with a 3 attack chain, so a very small buff overall, but how the damage applies in a less upfront bursty manner. Keep in mind this is a late game value where the marksman has 6 items, so that means values below 100% crit chance is a damage nerf when the attacks do not all crit.
This also brings up the damage floor slightly since the increased damage applies on non-crits as well and skill expression of the marksman a little more as they are playing around 3 attack procs against the same target, demanding the player to focus down a target (tanks) and not just doing crazy amounts of damage for attacking anyone at anytime. And yes, this damage increase applies to Runaan's Hurricane's attack targets as well, the mechanic is not like Vayne's Silver Bolts and last on targets for x seconds so attacking the target refreshes the duration until the proc goes off.
This is just one idea out of many. But a shift in how marksmen deal damage, especially with Infinity Edge, is needed and making Infinity Edge an item that requires other items with it to function well.