This is dependent on you having creatures, but as long as you have like 3 of them, this will feel really good -- and if you have more it's absolutely insane
You can play Norman Osborn early, build up some counters with connive, then transform it into a beefy, evasive Green Goblin
Croagunk DC - Jab 30 Toxicroak D - Pierce Prick 30 DC - Jump Uppercut 120 During your next turn, this attack does 50 more damage
You can also tap your opponent out to fog them for a turn or return a permanent to your opponents hand or save your threat
Condition Disclaimer: Cards are not guaranteed to be in 100% perfect condition
Theres obviously some luck involved here, but in a lot of decks, this should let you end the game on the spot