Shining Gyarados is quite frightening if you put yourself in the boat. Imagine being out there in the middle of the storm and giant Red Gyarados pops itself out as thunder, lightning, and huge waves scare the crap out of you.
This one already looked dark but it actually has a Komiya quote from an old illustration book, which makes it even more distubing:
“Even though they’re round and chubby and look calm, the moment I read the setting - ‘If it smells something enticing, it dashed off headlong to find the source of the aroma…’ - I knew there was no other option but this. When they take action without considering the consequences like that, I wondered why they became so desperate and fierce-looking. I was thinking of what a terrifying thing instinct can be as I drew this illustration.”