leblanc..

Literally can almost one shot with 1 skill plus a lich bane.

Can almost?

Firstly - she should certainly be able to 1-shot pretty much any squishy if she smacks them with a Lich Bane proc after her combo. Pretty much all other AP champions can do the same.

Secondly: LeBlanc is 100% useless if she can't 1-shot.

When it comes to damage rolls:

Most AP carries have the AoE power where they can shave off a solid 50% of the enemy team's collective health with their combo. Those that have issues getting their usually apply more and more potent debuffs that are generally more devastating than damage.

All AD carries can take out a collective 50% of the enemy team's health with auto-attacks and decent positioning.

Most assassins and fighters have strong enough auto-attacks, enough AoE, and re-setting mechanics to reach a solid 50% of the enemy team's collective health.

LeBlanc is pretty much capped at 20% of the enemy team's collective health. If you get the same kind of flawless situation where other damage rolls obliterate a solid 60%~70% of the enemy teams collective health, "maybe" you're getting 30% of the enemy team's health as LB and hopefully that involved a half-health target.

If LeBlanc is almost 1-shotting a single target with her combo and lich bane, she's not even hitting 19%. Which means she's actually completely useless and pretty much dead-weight. As a damage roll with negligible CC/AoE, essentially all LeBlanc brings is single-target damage.

Wait when did we start building Lich Bane on Leblanc?