User blog comment:Luxionmk2/Researching Efficient Fusing/@comment-24914701-20140507195432/@comment-5007614-20140507202007

Fusing MAX level Burnies is not efficient compared to capturing and fusing 2 normal Mimics.

MAX Level Burny:
 * requires capturing a Burny
 * requires capturing and fusing 2,500 XP worth of other units (~10 normal units, or ~4 Nymphs)
 * the fewer the better, Zel-wise
 * Fusing this MAX Level Burny will cost upwards of 8K Zel to create and about 600XP is lost in the process.

Mimic:
 * requires the capture of two Mimics, which is especially easy in Wednesday's dungeon
 * Negative - Mimics are craft materials for evolving units

The negatives of Maxing Burnies outweigh the work involved. Use Mimics to fuse for XP if you don't need them for evolving. The idea behind Maxing Burnies (and other slimes) is to consolidate extra units into one to:
 * 1) Save Unit space
 * 2) Save Zel in high level XP fusing

I am finding that Zel comes so easily now, especially with Jewel Keys and constant Honor Summon events that I don't bother "banking" units into slimes to save on Zel. I just spend the extra Zel and get the extra XP. I have also invested my Gems in extra unit space :P