Arcane season 2, Act I's ending.

Much of the anger Caitlyn feels comes from the death of her mother in Jinx's attack but has been furthered by another central member of Noxus' Black Rose cabal in Arcane, Ambessa has manipulated her way to the top of Piltover's influence, but to what end?

Ambessa Wants Control Of Piltover - & Hextech

Ambessa Has A Goal In Mind

As of Arcane season 2, episode 3's ending, it is clear that Ambessa simply wants control over Piltover. She manipulated one of the surviving council from Jinx's attack in Arcane, Salo, into putting her in a strong position. By orchestrating more attacks against Piltover in Arcane season 2, episode 1, Ambessa used the fear and anger of Piltover's citizens as an excuse to rise in power. This coincided with Ambessa and her Noxian guards "saving" Piltover from this attack that she put into place, giving her a great deal of influence over the wealthy nation and, eventually, Hextech.

This is seemingly Ambessa Medarda's end goal in Arcane season 2. She already has a puppet councilor in her pocket in Salo and has appointed Caitlyn as a so-called general to enact martial law over Zaun. If the Noxian warlord's plans lead to the neutralization of the threat that Jinx and Zaun possess, Ambessa will likely rise even further up the ranks of Piltover's already-fractured ladder of power. She could do so by weaponizing Hextech and controlling it, allowing her ulterior motives to become clear.

Why Does Ambessa Want Control Of Piltover & Hextech?

In Arcane season 2, Act I, it was revealed that Ambessa fled Noxus due to a powerful force of witches named the Black Rose. Although it is unclear what Ambessa did to get on the Black Rose's bad side, it resulted in the death of her son. It is made clear in Arcane season 2 that Ambessa is scared of these witches and thus, desperate, explaining why she wants control over Piltover and Hextech.

Using Piltover's incredible resources, Ambessa could fight back against the Black Rose. This would only be aided by Hextech weaponry, which is a combination of the magical and technological properties of Runeterra. Therefore, Ambessa is likely seeking total control over Piltover in Arcane as a means of amassing not only the city's general resources but its Hextech weapons too, all as a means of fighting back against the dangerously powerful cult that is trying to kill her.