The restriction means you don't have a critical mass of good proliferate cards to work with nor is it easy to focus on a specific type of counter, like loyalty counters (Superfriends) or +1/+1 counters -- it's possible , sure, but not optimal
Using the Energy Trans ability of Venusaur, paired with Pokmon Center, you can move your energies around anywhere on your board, allowing you to use Pokmon Center to heal off damage, without the downside of discarding Energy cards, so long as you move all those Energy cards to an un-damaged Pokmon first
The AI Pokemon generator is great for making custom Fakemon images
My personal favorite battle, Invasion of Ikoria, offers a flexible ability on the front that scales at different points of the game, and then sets up an outright win on the back with a giant creature that features a unique ability of its own to push through massive damage against your opponent
When new cards drop or the meta starts adapting, a deck that felt smooth and unstoppable last week can suddenly feel a bit clunky or get pushed aside by something faster and more consistent
If you're thinking of trying out this format, there are quite a few banned cards: Balustrade Spy Bloodstained Mire Expressive Iteration Felidar Guardian Field of the Dead Flooded Strand Geological Appraiser Inverter of Truth Karn, the Great Creator Kethis, the Hidden Hand Leyline of Abundance Lurrus of the Dream-Den Nexus of Fate Oko, Thief of Crowns Once Upon a Time Polluted Delta Teferi, Time Raveler Undercity Informer Underworld Breach Uro, Titan of Nature's Wrath Veil of Summer Walking Ballista Wilderness Reclamation Windswept Heath Winota, Joiner of Forces Wooded Foothills MTG Historic banlist Historic is a digital format for MTG Arena, and is the app's largest constructed format, consisting of both old and new cards