Anti-Venom. Y
Save the gem. Take shuri.
Get gentle or antivenom. My shuri is r3 unduped. Outside unblockable specials it's not needed.
They both are nice addition to roster, are helpful in monthly EQ.
New champ is better 95% of the times, in your case yes new champ is better.
it's not tricky at all anti venom is obvious choice here.