The rulings have always said that you can't use a fusion substitute for a non-named fusion material. So you can't use Versago for the dragon-type monster in Buster Blader or for the Dragon type monsters in Five Headed Dragon. You also can't use more than 1 fusion substitute on any fusion summon.
lmao people want to summon a beuwd with 3 of these
People saying it doesn't work, what are you trying to do? Are you trying to use 2 fusion substitutes? Are you trying to summon something that says it can only be Fusion Summoned with the above Fusion Material Monsters (Ryu Senshi for instance) with this card? Are you trying to fuse with the Spell card "Fusion Substitute" using monster(s) from your hand?
None of those actions are possible, and that's no bug.
This is a good card especially because it can be used as a fusion material to save a card from being polymerized and be used later. It can also speed up the time it may take to draw the fusion materials and polymerization/fusion gate because it's an alternative to draw instead of the 2/3 fusion materials.