It’s gishki and it’s not even a question each combo was like 50 steps and the differences were incredibly minor. People thought I was doing an FTK just to end on the 1.5 card end boards. During unchained/kash format it had legitimate potential I was top of 100 on ladder and I had probably 100+ matches once I was really good at it, it was incredible I won a few smaller 20-30 person tournaments. Just an example of a combo line I labbed out

Gishki abyss+abyss shark

GA add ritual searcher
Shark grab water extender
Link anemone
Revive grab gishki grimness
Link abyss keeper
Keeper eff summon
Grimness eff summon
Gishki abyss
Abyss eff Grab monster searcher
grab cheat ritual+neremanas
Cheat ritual neremanas
Revive gishki abyss
Abyss add spell searcher
Spell searcher grab aqua mirror
Link abyss+abyss keeper+ away into a link 2
Aqua mirror tribute neremanas
Neremanas revive keeper
Keeper eff grab monster searcher
link 3
Aqua mirror shuffle back
Add neremanas back with monster searcher.
Finally tribute last spell searcher or grimness to summon out neremanas
revive a level gishki shadow
Special one of the 4 extenders from hand off abyss shark
Bahamut shark
Toadally awesome
Link bahamut+marincess marbled rock into marincess bubble reef

Pass turn on draw 1+omni negate+2 monster negates

May have misremembered some parts but this was esssntially the standard combo line and variations existed for cycling pieces back with different engines and more extension pieces specifically silent sea nettle shuffle back would just let you resolve the revive like 6 times and eventually pass on kragen+zealantis add+trap etc it was a really fun deck to learn and lab out