Xerath has a mana regenerating passive that rewards him for getting up in AA range when he's suppose to be this long range artillery mage while Lissandra is the exact opposite. So why not give them both passives that will enhance their play styles?
MrBuffington22 votesI think Lissandra needs a new passive, but the reason Xerath has his passive is so he'll have some way of sustaining his mana, but also requires him to take a bit more risk to utilize it. Otherwise he'd just sit under his turret and clear waves all game, which makes his gameplay really boring and non-interactive and reduces his counterplay. It's also the reason he has 525 range instead of 550 or something higher.
Jungle Lux God17 votesXerath's passive is supposed to give some incentive for him to interact more with the enemy laner.
It's not super interactive for Xerath to have the capabilities to poke someone down without meaningful interaction, especially with spells as strong as his. As such his spells need to have high mana costs to compensate for his ability to poke someone down with little risk.
His passive is designed to give him the ability to utilize his abilities more often at the expense of having to interact with the enemy laner more often, usually in auto attack range.
Give him Lissandra's passive, and either his costs would need to be dramatically increased or his mana pool would need to be dramatically decreased, and suddenly he can only cast a couple spells without the passive.
Slamurai Jack2 votesExactly. You have to think about it from the perspective of both the champion and their opponent. Of course Xerath would prefer the passive that doesn't require him to interact with his opponent because he doesn't want to do that anyway. The goal of champion design isn't simply to make the best, most synergistic kits possible. It's to create a compelling and enjoyable experience for the player while also providing meaningful points of interaction between a champion and their opponent.
N0rth Wind2 votesi wants ti gibs xerif ze abiliti to haf mana rigen laik his siting in ze base fo0ntain but when his in lein, lellllllll
no but seriously as a relatively experienced Xerath player, NOT having a mana regen passive would make his laning a chore, but making it easier to proc would make it hell for the enemy, and I'm saying this from Xerath's perspective.
I'd only wish for his passive to be a % of his max mana, late game it gets prettu useless :(
DorkunedAuras1 voteslate game he also has mana regen items, so the passive is mostly useful in lane.
N0rth Wind1 votesYeah :( Both Xerath's and Lissandra's passives really fall off later on in the game and basically you forget about them :/
ModWulf Helhammer5 votesYou obviously don't understand balance.
The point of Xerath's passive rewarding him for going up close is to allow his opponents to actually do something to him. If he could just stay back out of range of everyone, so you realize how unfun that would be?
It's the same reason Lux and Ziggs also have AA centric passives
LatetotheRace4 votesNo
Trídent2 votesgood idea
Liss' passive on Xerath needs to be modified tho
Transgressor2 votesNo
YumaS2Astral1 votesThis reminds me of the times that people were asking Riot to switch 
and 
passives
In the end, Ashe's passive was completely changed, while Talon's passive remains the same, and it is somewhat useless now because he no longer has a silence and can't apply a CC himself.
ModWulf Helhammer9 votesSlows
A Miss Fortune2 votesThat 0.25 second slow.
Jungle Lux God5 votesTalon's passive never applied on his silence, but does apply on all of his slows.
ShadowParker1 votesI like the idea. But at the same time, I feel like Xerath being forced to auto for mana gives opponents windows of opportunity versus him being able to stay in the back forever. Yannow?
NostolgicSkies1 votesi always thought lissandras passive should be something along the lines of "spells cast by lissandra apply frost Slowing the target. each spell hit refreshes the duration of frost and adds another stack of frost. Frost slows by 10% for each stack stacking up to 5times." something like that would fit her spam kiting like kit better then a generic mana passive.
