Despite his lack of knees or elbows, I enjoy Krika for how much you are actually able to do with him; so many intimidating poses. His general silhouette is also pretty unique compared to many villains prior and really gives him an imposing presence.
Character wise, he also had great potential, as it was interesting to see a Makuta with actual dignity. He seemed like he was willing to do good but was weighed down by his inherit 'evil' (which sounded a bit ridiculous to me). It was a concept that would've loved to have seen explored more- if only he weren't killed off in an instant.
Kojol is another character I would've personally liked to have seen explored more from what we've learned of him. His signifigance in engineering the virus Teridax used to crash Mata Nui's systems and leading the raid for the Avohkii itself made for a character with some interesting background. But we never got to learn anything about his character and personality other than: his assigned region is Artakha........ he's secretive.......... he creates air and sea Rahi.