For me atleast, Andorne is selfless idealist whose obsession is finding an answer and 'saving' others, as shown in GA. He did not seek for destruction of Laterano, he simply want an answer. Why only Sankta is worth saving? (being welcomed to Laterano). This behaviour probably stems from his past of failing to help people in his hometown. His line when he confronted the pope; "Why is Tidal Stone Town only worthy of destruction!?" pretty much suggested that.

I love his development in the event from the angry, confused and lost idealist into someone standing by his ideal: raise the fire that could save the lost in the dark.

I hope we could see him again, well we might since his gun is with Fiametta, being repaired at Rhodes Island and I do want to know about what happened at Kazdel ruin from his perspective as well.