Generally, no, but there are some exceptions, so read on ...
The assets that come bundled with RPG Maker (any version) or IG Maker or Game Character Hub can absolutely not be used in any other engine, even if they are edited, and no matter how much editing is done. They are for use in RPG Maker / IG Maker / GCH only.
SOME packs are able to be used in other engines. These are listed on the store page through Products > Resources > Non-RM. ONLY products listed on that page and purchased for the price shown there (which is higher than the price for use in RPG Maker) can be used in other engines. If it's not on that page, or it is on that page but you bought it from the other link for the lower RM-use price, you cannot use it in other engines.
Hope this clears it up.