Question about this Zekrom?

If I was to fuse this with a Kyurem that also had a special background, will the Kyurem Black have an even more rare special background or just the one the Kyurem has?

If I was to fuse this with a Kyurem that also had a special background, will the Kyurem Black have an even more rare special background or just the one the Kyurem has?