Even after the release of S6, I can confidently say that Finnegrin's Wake is my favourite episode in the series (something I'm expecting only S7 to knock out of top spot). From a clever play / double meaning on its title to the fact it has a plot beat for Callum and Rayla I'd been thinking about since before S4 came out, seeing it happen on screen was truly a dream (nightmare) come true.
5x08 lets Finnegrin step into the role of a main antagonist and he shines in every scene he's in, continually pushing Callum to higher and higher stakes / more difficult choices. The way it weaves in previous fears / themes from Callum's dynamic with Aaravos is brilliant and seamless, and the interplay contrast provided with the Amaya-Janai-Karim plotline helps the choices and moments in each hit all the harder emotionally every time. 13/10, easy.