Lost Sword Rerolling: Are you aiming for waifu or a meta unit?
Make sure to check our tier list to see if the current rate-up unit is worth rerolling for.
Is the current rate-up banner meta?
What type of characters do you like?
For Knight teams: Lancelot and Palames. If you prefer a Wizard team: Tiamat is the only unit worth rerolling for.
Dian Cecht if you are running Knight teams, or NEO Bedivere if you want a support that fits into any team composition.
Belsey is a great option that also provides debuffs and acts as a sub DPS, while Galahad is the best tank for Wizard/Ranger teams.