What if Akali gained a shield instead of a heal?

Akali's self-healing is massive. With an empowered Q and Gunblade equipped, she can heal herself for half of her health bar off of a minion wave.

What if, instead, she gained shields? It would do the same job of giving her more HP for landing her Q, but the shields would fall off after a certain amount of time or decay. They would help keep her alive while fighting, but they wouldn't last between fights.

This would do a number of things to Akali. For starters, her lane sustain would be worse. Between her lack of mana and immense self-healing, she never really has to leave the lane, ever. Having non-permanent shields would fix that. Mages who manage to chunk her down would be rewarded with forcing an early back or opening her up for an all-in, just like any other midlane assassin.

Second, it would reduce her split push power. Akali loves to split push while her team is doing objectives, since she has the sustain to do so and the ability to easily 1v2, meaning the enemy has to send three people to stop her push, which guarantees either the objective or a tower for her team. Shields would let her tank minions, but they wouldn't heal her up to full for when she rejoins her team.

This would also reduce the ease with which she can tower dive. Akali can leap under tower and tank several shots for the kill after her smokescreen has run out. On most assassins, this means they have to back, but Akali can just Q the minion wave twice and be totally healthy and ready to continue pushing.