With connive X, you draw X cards, discard X cards, then put a +1/+1 counter on the creature for each nonland card you discarded
Youre gaining an extra card in your hand, potentially finding what you need for your strategy, and developing a 4|4 body on the board
Its second-best feature is to double the triggers from the doctors abilities, so The Tenth Doctor can get plenty of Allons-y triggers, while The Ninth Doctor can get an extra upkeep, and so on
Historical impact on the game is the most important, especially at the highest levels, along with future impact, but I also considered anything else that makes you the best
Upgrade Tips This is a great shell to start upgrading for Standard control
In addition to Hakbal, the deck gave merfolk some new tools, with Deeproot Historian and Singer of Swift Rivers