OOC: Actually, I'd pretty much shot my bolt there with that last card. I think you made only a couple mistakes, including declining to use Gishki Beast's effect in the last turn - looking at your hand, you could have resummoned Gishki Vision with Beast, discarded Shadow for Aquamirror, activated the graveyard Aquamirror to recover Gustkrake, and summoned Gustkrake using Aquamirror on Vision, removing another card from my hand and baiting a response yet again (I assume that's why you stopped so often), all while still keeping Beast and Ariel available to pull out Roach after. Given how many summons and other effects I had ignored to date, it was understandable to underestimate my last facedown card, but the fact that I used it at the cost of 4000 LP just to prevent a monster that I could have run over under normal circumstances denotes just how much trouble I was in.

At any rate, looking through your deck, let's see. Evigishki Tetrogre is kind of an amazing card in my opinion; for Gishkis, Graveyard searches and recovery are extremely powerful, and my old Frog/Gish build abused the ability to instantly and automatically search either an Aquamirror, an Evigishki (for a used Aquamirror), Treeborn Frog, or Fishborg Blaster (sadly banned; c'est la guerre) for all sorts of synchro/ritual shenanigans, especially since ignition priority still existed in the TCG. Even in pure Gishki builds, the first two are still useful, and pulling out additional monsters for Salvage is also a good trick. Given how many 6-stars you run, Preparation of Rites is useful, reducing the need to search Evigishki monsters while permitting another way to recycle Aquamirror to your hand. Gishki Beast should probably be run at 3; it's just so useful for recycling and overlays. I like Gishki Marker as well for recycling capabilities, but it's not as necessary. Finally, I've oddly never been fond of Moray of Greed, despite its theoretical usefulness. More like than not, it's my own gameplay style rather than the card itself, but I tend to deplete my hand too much. Still, I can't think of much to replace its draw power; I used Hand Destruction, but that was in a deck that relied on that now-banned Treeborn/Fishborg combo for mass Formulas as well.

Still, I haven't played Gishki in a long while; I did dig up my old deck, only to find that it uses cards banned in March 2011. A lot of new cards, too, so my advice might be a little outdated.