Fusion Monsters Special Summoned without “Polymerization” while “Fusion Gate” is on the field are still considered properly Summoned by a Fusion Summon. So they may be the target of “Monster Reborn”, “Call of the Haunted”, etc. (This does not apply to Fusion Monsters Special Summoned by the effects of other cards, such as “Magicial Scientist” or “Summoner of Illusions”.)