Personal recommended changes for each legend.

Ash - Change makes no sense, "Barely ever gets used, lets make it have a 3 minute cooldown for whatever reason and make it infinitely more complicated by adding an item to inventory"

Makes Zero Sense. she doesn't need a change

Bangalore - is a decent change, I guess for more experienced players know the pattern because it always lands the same from where the grenade lands.

Bloodhound - is still super strong, no need for another buff.

Caustic - Is not in a terrible place at all. Dominates indoors yes, that's his advantage, definitely not weak outside. Doesn't need to be more complicated by adding stacks of whatever to wherever. Stacks of toxin makes no sense since thats what it already does? the damage ramps up the longer they are in the gas going 5,5,6,6,7,7 etc

Crypto - Follow mode is nice, thats about it. Seems a little powerful if he gets to scan whoever he sees and could be a bit OP if he just gets to ult on himself whenever he wants to with almost 0 counter play.

Fuse - NO He should not stack THREE grenades. thats insane, its bad enough when you are in a room and 12 arc stars fly through the window. 2 is enough. 

Gibraltar - "Gibby is in a bad place, and has been since season 0"  From this comment alone I don't think I can take you seriously and think you are talking out of your *.. He's always has been so powerful. The "Nerf" was just a buff to one legend being able to destroy it. That there is very low chances as Maggie isn't picked often. Your change idea is crazy and unpractical.

Horizon - I agree that her aim should be nerfed as not only she has vertical movement she also has horiztontal movement when in her tactical making her hard to hit when she's using it. feel like it should really only be used for gaining height instead of just a means to be untargetable while having perfect aim.

Lifeline - Passive change makes sense, I like the idea but you can literally just place tactical straight after reviving and it will do the same job. ultimate change - its kinda meh, the carepackage just gives better loot than what you currently have so i guess its not a huge jump.

Loba - Sounds complicated and unnecessary 

Mirage - Good buff idea for tactical and passive as it is literally my idea from another post, the aiming decoys may be overkill. but theres no way to tell without it being in the game and testing.

Newcastle - No, stop trying to make him more powerful than he needs to be.

Octane - Hes fine

Pathfinder - I think he just needs an entire passive rework at this point. finding the next next ring isnt useful as much as youd think unless you have defense characters to hunker down.

Rampart - she is niche but really powerful when used correctly, creating cover whereever you like is 

Revenant - Dont see a point in wall hanging, if you are standing still on a wall you are easy picking. needs something else.

Seer - Passive change nice, Ult change makes no sense

Valkyrie - Just no.

Vantage - Does too much damage with sniper Agree it should be less.

Wattson - Too complicated.

Wraith - Shes fine