In the Japanese GoLion version, Sven/Shiro actually died, so the Voltron in this Death battle episode may be a combination of both the original GoLion and the syndicated Amercan version.
However, the episode stated that Sven, or Shiro in the original GoLion version died.
The episode featured the original Mighty Morphin’ Power Rangers, which was syndicated from the super sentai series, Kyouryuu Sentai Zyuranger.
In the Americanized Voltron version, they just presented Sven/Shiro being gravely wounded before being replaced by Princess Allura.