Overgeared Hero tier list: Bjorn moves from S to A

Bjorn, the free Legendary Warrior from the Surviving the Game as a Barbarian collab, drops one band to A. His damage needs a long fight to build, and most chapter fights are short. Nothing else moved.
Why A, not S
Bjorn's damage comes from the Max HP he gains during a fight. Gigantization adds up to 30% to all of his damage as that Max HP climbs, and Flesh Burst hits harder for every 100% of bonus Max HP. Both start low and grow.
The fastest chapter builds try to end a fight in about ten seconds, and Bjorn is still climbing at that point. Rose, the S-tier Warrior, has no such wait: Impale sends her Spike, Poison and Burn through Block from the first hit. That gap is worth a band.
Where he is still the right pick
Long fights. The collab's Rafdonia Labyrinth stages are built around them, and a backpack of Spiked Armor, at 40% Max HP each, feeds both of his skills there. In chapters, White Wolf Captain's 30% Haste and Tiger's 25% weapon damage cover his slow opening.
His 4-star Skill Link is unchanged. It lends Gigantization to every Warrior, so the shards are worth claiming whichever Warrior you play.
Bjorn
Rose