Do you have Chrona? I remember you are a ladies fan xD so, her ultimate does a decent dps physical attack on FH. And Driller is also perfect here. Crusher is not good at that PP level from what I have seen.
Also if you by any chance have Radulf upgraded, you can use him along magical heroes to deal damage to FH when his curse is present. And he is useful against Deathcrawler because of the curse (DOT plus 10% extra damage) and his dps ultimate and a little to Gizmo for the DOT (not sure if the 10% extra included dot from other heroes though), so the items would not be totally wasted.
The damage you deal is irrelevant. Only the number of hits in egg form matter. Number, not damage. Your heroes could be purple fusion with no items that it would still work, if they survive that is.