Saga , running on k8s consuming GCP pubsub events

Hey Community,

We need a light implementation of the Saga pattern. I thought of using Axon. It needs to consume and produce events from/to GCP Pubsub , Rollback is not required (We aggregate events, to a single event in time). Preferably an Eventstore would not be required. (But a SagaStore would be).
Question is, what kind of effort is foreseen for the GCP pubsub integration, and can we run a Saga without event store ?

TIA Christophe