Board Thread:Tips, Tricks, and Questions/@comment-190.153.135.104-20131123191034/@comment-74.75.133.40-20131124183401

Theorhetically yes if it was the same boss, but to date there have been no repeated raid bosses. For example I have 3 pets that did bonus vs Giant Abysson during Celestial Towers, but they had no bonus vs Giant Megataur even though it was also a Celestial Towers event. The only event monsters that have carried over between events thusfar are for troops wars.

I wouldn't count on them ever deviating too much from this model, because people going crazy for event grabs to get an edge is probably a huge source of revenue for them. If they let you use old monsters they lose all that income.