Experience provided per monster per fuse.
The amount of experience provided per monster increases as they gain level. For example, a level 2 Ul-Khum-Khum gives more exp than a level 1 Ul-Khum-Khum and so forth (143 vs 128). In addition, higher SEF fighters give slightly more exp than lesser SEF fighters even if they are the same level. For example, level 5 Diggo with 1 SEF gives 177 experience while a level 5 Diggo with 0 SEF gives only 174 experience. In terms of base experience provided, the biggest factor is usually the overall stats of the fighter.