yugioh card hand limit End Phase Discarding for Size Hand size limit effect explanation?

All this week (and shortly into next) brand-new cards will be popping up on DailyMTG and around the internet, so stay tuned to the Card Image Gallery and the list of preview outlets to find all the cards coming in Core Set 2020

Experiment One

Modular Monstrosity What keywords am I allowed to choose

Were not really sure what else we should say about this

Though Yugi managed to weaken Atem's God Cards enough that he could safely attack and destroy them, the elder duelist flipped the script when he revealed Mirror Force, completely changing the battle's momentum

509.5g An ability that reads Whenever [a creature] attacks and isnt blocked, triggers if no creatures are declared as blockers for that creature