User blog comment:B214/Volume 22 spoilers/@comment-28087053-20170114184806/@comment-80.116.68.91-20170115015416

When Ddraig and Albion, before they were defeated and sealed inside the sacred gears, were strong enought to be ranked among the top 10 of the strongest beings in the world.

Indra is right now considered one of the top 10 beings in the world, but I don't remember if they said he is stronger than them when they were alive with their bodies. But, if I remember correctly, Indra's strenght should be 4 times greater than the one of the current 4 great satans together. So I guess Indra is stronger than them (at least individually).