Blocking it or attacking into it and coming out ahead is basically impossible, and your opponent has to have removal that doesnt do damage to ever feel good about things, otherwise theyre going to be losing several permanents just to take out the Obliterator Im not in love with this
Strong lands to craft for an enduring collection include the surveil lands from Murders at Karlov Manor, the fetch lands from Khans of Tarkir , and the shock lands from Guilds of Ravnica and Ravnica Allegiance
Ponder is one of the most famous cantrips, though there are dozens available
Emissary Green seems overcosted at five mana for a 3/3 that must attack before you get any benefit, either Treasures or +1/+1 counters depending on how all the players vote (you should vote security yourself to boost Emissary Green large enough to survive combat)
For each opponent, exile up to one target instant or sorcery card from that player's graveyard and put a page counter on it