Lissandra vs Sea Beast Weapon: who would win?

Sea Beast Weapon favored — Slight edge (~55%)

Lissandra · League of Legends · Pentakill Universe

Tier

HIGH 6-A

Attack Potency

Multi-Continent Level

Speed

Massively Ftl+, up to Omnipresent

Durability

Multi-Continent Level

Sea Beast Weapon · One Piece · Base

Tier

5-C

Attack Potency

Moon Level

Speed

Subsonic, up to Speed Of Light

Durability

Moon Level

A heuristic estimate from normalized VS Battles Wiki stats: tier, attack potency, speed and durability.