Let's say that some whale got to 10k HP base HP, which might be possible. Not sure. Anyway, that means he needs 400% HP.
That's Union event, so 100% get.
Maximum Defender from FLB weapons is 21% each, so 210%.
Double 40% Eidolons, 80%.
... he's still only at 390% HP modifier...

Honestly, I don't understand how that image has been made