You're right, Goku couldn't sense Dabra's ki--but based on how Dabra moved when he attacked them outside Babidi's ship, Goku estimated that he was ~ Cell... And we were ultimately given no reason to doubt his assessment.
It's also worth noting that Goku stated Dabra was tougher than he first thought, after seeing him use magic against Gohan:
So I'd say Dabra was Perfect Cell-level, at the very least--possibly a bit stronger when you factor in his magical abilities.
Originally posted by Galan007
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It's also worth noting that Goku stated Dabra was tougher than he first thought, after seeing him use magic against Gohan:So I'd say Dabra was Perfect Cell-level, at the very least--possibly a bit stronger when you factor in his magical abilities.
But note, *after* the tougher comment, Vegeta states 'Gohan still shouldn't have this much trouble, he was stronger as a kid.'
Which indicates SSJ2 Kid Gohan is in Vegeta's opinion, reasonably stronger than Dabura.