Suggested by Destroyer Janemba is a very dangerous villain since his abilities transcend dimensions. It’s also worth noting that his speed and power were enough to even overcome SSJ3 Goku. That being said, Broly is on a completely different level here. He was able to take on Super Saiyan Blue Vegeta and I expect he will only continue to get stronger from here on out. While this may have been different before the Super movie there is no way Janemba can win now. Broly wins.