Hi there, I've heard someone is looking for feedback :D
Sorry for arriving late, I rarely visit Mobafire Discord nowadays :p

Okay so to your guide, I can definitely see a well-lit spark of hard work right here! Your items section is easy to follow and right to the point. The matchup section is pretty detailed, you have listed every support matchup with unique tips. Your cheatsheet is short and easy to understand, just the way it should be :D Overall what you have written here so far is not bad at all. I am having trouble loading your combo-videos though, it might be a problem at my end but it can also be an error in your code :/

Your guide could also see some life if you know what I mean :D A text is an awesome thing, but you know what is also just as awesome? Images! Images and colorful text and a thematic! One very wise person once said that a picture is worth a thousand words. No clue who they were, but they certainly made a very good point, doncha think? :D If I were you I'd certainly add some to make it more fun for the eyes to look at. More color would be also great! As long as you keep it thematic and don't go overboard with it - color can only make a guide better! You can also toy with different sizes of text, headings, and whatever your creativity comes up with!

Sadly I am not a Nautilus player, so I can't really 100% accurately evaluate the viability of your build. A part of me was a little bit skeptical about Randuin's Omen, considering how expensive that item is, but after consulting it with u.gg I must say I was wrong - that item is worthy of Nautilus's inventory slot - just like all the items you are recommending! So I see no problem here :D

Overall I think your guide is off to an awesome start! I really hope you'll keep it up and come up with more updates, more chapters, and more content! There are so many topics a Nautilus guide can cover (engaging, positioning, teamfighting, runes, laning phase, mid-game, late-game just to name a few). So I sincerely hope you'll continue teaching aspiring Nautilus players the ways of the sunken titan, even after the contest ends :D

Best of luck on the Rift, especially in the contest <3
Have a ravishing day!