ok i KNOW they havent FAQed it yet, but my friends and i have a house rule that feats are legal as soon as they are posted online.

Does anyone have a read on using sidekick with JSA (or defenders) to share defense value down the line? for example. KC Green Lantern SKs V Stargirl (with ESD shes now 22, can she then share the 20 with mr terrific if hes next to her?

text says "The second character uses the first character’s defense value instead of its own when it is attacked by an opposing character." and obviously JSA says "UNMODIFIED" defense value.

My friend reads that since the Sidekick "uses" the defense value it "replaces" and therefore you could do that, my read is that you can't, since the card clearly states you are NOT replacing but using.

kinda the same argument from two directions? any (obviously unofficial) thoughts on this?

Uses, replaces... they are both pretty much the same thing.

However, the *real* monkey wrench in your plan is the the phrase "...when attacked by an opposing character..." Here's why: until Stargirl is attacked, she doesn't have the 20 DV of GL. So if Mr. Terrific, attacked all by his lonesome, borrows her DV, he is only borrowing her natural 16 DV. Side-kick won't activate until Stargirl is attacked. An opponent would have to target both Stargirl and Mr. Terrific with the same attack for Mr. Terrific to use the 20 DV.