Silencer
Silencer adds some extra Damage to the
Submarine and greatly reduces its Cooldown. Speed is the most important part of this strategy, because you're essentially fighting with seven items to their ten (until the
Dam goes off).
Aside from
Dam,
Silencer should always be the priority upgrade target. The good thing is you'll likely have access to
Silencer earlier, giving you more opportunities to upgrade it before
Dam has even been acquired. The extra Cooldown reduction is far more valuable than a bit of extra base stats on the
Submarine.
Pearl
Pearl fills the final slot as a very fast Small Aquatic item. Its Shield comes second to everything else, as really the entire purpose is just getting
Dam to activate as soon as possible.
Upgrades are irrelevant since only the activation speed matters. Don't feel the need to search vendors because even a Bronze tier will do just fine.
Flashy Pilot
Flashy Pilot is actually one of the strongest Crit scaling skills in the game. However, the downside is it's limited to Vehicles, which aren't exactly common.
However, alongside
Submarine this is an incredibly fast and reliable way to reach 100% Crit. In this particular build it's even more
effective than
Building Crescendo, as you realistically only have two active items (not including the
Dam).
Improvised Weaponry
Improvised Weaponry is your reliable form of scaling and gets twice the value with
Submarine. It's especially important against matchups with Large items, as they can likely still contest against you after the
Dam goes off.
At that point you can't rely on
Shadowed Cloak or
Silencer, so
Improvised Weaponry comes in clutch. Plus even if the enemy lost their entire board, if they happened to stack up enough Burn/Poison, you may need to end the fight before the sandstorm kicks in.
Blizzard
Blizzard is a really powerful skill dropped by the Frost Street Champion PvE Encounter. It applies an immediate Freeze to all non-Weapon items at the start of the game. While this will slightly hinder your items, in most cases it should be worse for your opponent.
This allows the
Submarine to get a head start and start Hasting/scaling before any other items can act. In Kripp's case, it's also applying Slows to the board, making the opponent have an even rougher start from the get go. Exactly what this build wants!