mewtwo gen 1 pokemon card First Edition the trusted official grading guarantees its condition PSA 1 - Mewtwo 1999

If you look at the most popular commanders for Gruul, there are some telling signs

Brawl Legal Vintage Legal Timeless Legal Commander Legal Pauper Not Legal Oathbreaker Legal Penny Not Legal Toolbox Notes and Rules Information for Cloud, Midgar Mercenary: Triggered abilities use the word "when," "whenever," or "at." They're often written as "[Trigger condition], [effect]." Some keyword abilities are triggered abilities and will have "when," "whenever," or "at" in their reminder text

So, if you have a 2/2 with deathtouch who attacks and gets blocked by a 4/5, both creatures die

Then you can tap one with a mana to pump an Assembly Worker that is attacking by +2/+2