Archangel of Thune 5/249 Magic 2014, Mythic Rare A five mana 3/4 with flying and lifelink is a fine body, but the third line is where it gets silly, which is whenever you gain life, put a +1/+1 counter on each creature you control
A few early trial runs showed me that everyone at the table freaks out about Planeswalkers, even when they're not doing anything terribly threatening

Admonition Angel Adventuring Gear Aesi, Tyrant of Gyre Strait Akoum Firebird Akoum Hellhound Akoum Hellkite Akoum Stonewaker Ambrosia Whiteheart Architect of the Untamed Attercop Avenger of Zendikar Baloth Woodcrasher Belligerent Whiptail Beorn's Hospitality Black Chocobo Bloodghast Boughside Wanderers Bristly Bill, Spine Sower Brushfire Elemental Calcite Snapper Canopy Baloth Canyon Jerboa Caustic Crawler Choco, Seeker of Paradise Chocobo Racetrack Claim the Kingdom Cosi's Ravager Courser of Kruphix Dancing from Dark to Dawn Down in the Valley Dragonback Assault Dreadwurm Druid Class Dnedain Rangers Earthbender Ascension Elfsworn Giant Elven Raft-Steerer Embodiment of Fury Embodiment of Insight Emeria Angel Emeria Shepherd Eternity Vessel Eumidian Terrabotanist Eusocial Engineering Evolution Sage Fearless Fledgling Felidar Retreat Fledgling Griffin Floral Evoker Gandalf, Shadow's Foe Genemorph Imago Geode Rager Geyser Glider Geyserfield Stalker Glacier Godmaw Gladiolus Amicitia Glyph Elemental Grappling Kraken Grazing Gladehart Greensleeves, Maro-Sorcerer Groundswell Grove Rumbler Guardian of Tazeem Guul Draz Overseer Hagra Crocodile Hedron Crab Hedron Rover Hedron Scrabbler Icecave Crasher Icetill Explorer Ior Ruin Expedition Iridescent Vinelasher

You can think of them like batteries, they provide the power you need for all your other, more useful cards