Harbor Serpent A 5/5 creature with islandwalk can be a pretty big threat, especially in formats with only 20 starting life
Next at the three spot is another pair of enchantments, this time both uncommon
Once it was decided that we were only exploring the mainline games, we made a spreadsheet for every game and filled it to the brim with every character, spell, weapon, monster, summon, and story moment we could fondly remember or that was so iconically FINAL FANTASY that it had to make an appearance
The only other thing you need is largely out of your control - and thats for your opponent to have enough collective willpower on their characters to withstand the Sheriffs pinging before being banished and halting your combo
Making artifacts while casting artifacts enables cards with affinity for artifacts like Thought Monitor and gives creatures like Urza, Lord High Artificer and Kappa Cannoneer all the artifacts they could dream of
When casting your countermagic is already good, getting an additional effect pushes you towards a win