Question about BLM limit break

[SeraviEdalborez]

Sadly only surecast will help you out. In beta we thought raging strikes helped but that was proven false. The only damage modifier is the party's combined item level.

Limit Break can't be interrupted by damage (the only thing Surecast prevents from interrupting you) so it doesn't have an effect on it either.

Going into more detail about the underlined.

Average weapon ilvl of the party is the only thing that affects limit break damage. A party with weapons ilvl 50, 60, 70, and 80 will do the same damage with LB as a party with weapons ilvl 50, 60, 70, and 80 with all other slots being naked. A party with higher ilvl weapons will do more, lower will do less.

It's for this reason that the least-geared DPS that you want to use the LB is the ideal person to use it. The party members with better gear can keep doing high DPS in the meantime. If roughly equal gear/DPS, DRGs are preferred to use melee LB over MNKs (MNKs will lose Greased Lightning on LB2 or higher), and SMN is preferred to use over BLM usually (BLM's fire or ice will generally fall off on LB2 or higher, though using LB after Flare > Transpose is one way to mitigate the downsides).