MANA CRYPT My personal pick as the most powerful card legal in Commander
The Pokemon Company Quietly Updated Its T&C This is the part most collectors missed
Archmage Emeritus Everyone's favorite Spellslinger trigger in Blue for Izzet, Jeskai or mono-Blue with Talrand, Sky Summoner is this four-drop 2/2 body
It's all free, so if you're a Pokemon fan there's no reason not to check it out, especially if you're a fan of the videogames who's curious about the TCG.
Despite these new solutions, older cards still keep their original text or updated Oracle text that says Regenerate. If you own those cards, the rule is still valid: you can pay the regenerate cost, you can save your creature from lethal damage, and you still get to keep it on the battlefield, albeit tapped
Anything else specified in the effect creating the tokens (such as tapped, attacking, "That token gains haste," or "Exile that token at end of combat") still applies