Gohan taking Cell's blast

[SSJ2]

When Gohan took SPC's blast how off guard do you think he was? It looked as though he was trying to grab Vegeta instead of blocking the attack. Was he completely off guard?

 

[Captain Cadaver]

Not very. He was still completely aware the blast was heading that way, unlike in actual cases of characters taking a whole lot more damage from unexpected attacks. What's really left up to debate is how important the angle of the attack was with him taking it without being able to put up an actual defence. Logically, it should make no difference whether or not he's blocking with a limb or the side of his body when Ki covers the whole body or what areas need cover, but instances within the series make note of putting up a physical defence being more beneficial such as Goku making note of how he didn't need to block Nappa's Ki blast before cancelling it out by just taking it.

 

[Papasmurf]

I think he didn't have any means to defend himself, and that did make the blast damage him more than it otherwise would have, but Gohan noted how much more powerful Cell became moreso than the fact that he took it without putting up any defense, so the blast was no joke either.

 

[Hector]

I think Gohan's power was reduced to 40%, which increased to 80% when Goku encouraged him and 90% when Vegeta distracted Cell.

 

[Captain Cadaver]

I think Gohan's power was reduced to 40%, which increased to 80% when Goku encouraged him and 90% when Vegeta distracted Cell.

Leaving aside the point of the thread isn't to discuss the amount of damage it caused to Gohan, Daizenshuu 2 states Gohan summoned forth "his strongest power" during the beam struggle, so he was at least at 100% of his regular full power when destroying Cell if not brought to greater heights. This is further reinforced by specifically the Gohan that killed Cell being used as a benchmark in instances such as Vegeta comparing SS2 Gohan against Kibito to him.