Blola was the Transcendent Eater. Not only was he able to revive the Mystic Path holders, but he could also generate Parute King Fruits when necessary, allowing the Mammoth Clan to build up strength faster.
Therefore, for such a strategic asset, Raaha would be keeping watch on him all along.
Based on what Inala obtained from Orakha, he knew that Raaha kept Blola locked up in a house that dangled from the tusk of the 1st Empyrean Tusk. Whatever Blola did was under Raaha's constant watch.
Hence, if Blola managed to arrive at the Brimgan Empire, it could only be possible after he reached the 2-Life Stage. Either his second body legally obtained Raaha's permission to arrive here or through some scheme, he managed to sneak a body away.