Vantage has an out-of-balance ability kit
I have been playing Vantage quite a bit lately to see how she plays, and then tried playing Alter. And it is more than evident that some characters have extremely out-of-balance ability kits.
This means that of the two abilities that a character has, one is significantly more powerful than the other.
With Vantage the issue is that her ultimate sniper does too little damage, while her jump ability is too effective as an escape tool.
Vantage tactical bat jump
I recommended removing the ability to send out the bat and immediately jump after it with Vantage. It is too easy to quickly escape dangerous firefights with this ability. Changing it so you first have to send out the bat and then have to hold the jump button separately ensures it takes Vantage a bit more time to jump and rewards Vantage players for pre-placing the bat. It effectively makes Vantage more unique from someone like pathfinder by adding an element of thinking and planning ahead.
Vantage ultimate sniper
I recommend increasing the damage on the first shot to 65, and the damage on marked targets double that, so 130. This means if you get hit twice by a Vantage ultimate and you have purple armour, you will suffer 195 damage, but will not be downed. This change would simply make the sniper do a bit more damage without crossing a new break point (break point = number of hits to kill) which is pretty important with high single shot damage weapons.
I know its unrelated, but Alter’s ultimate doesn’t feel very powerful. The removal of allowing downed people to teleport to the ultimate portal feels like it has made her ultimate useless. There’s absolutely no point in having a teleport fallback in a game in which you constantly have to move up to keep up with the ring.