If you didn't know the backstory to Phelddagrif, you wouldn't understand the card name or why it's so weird, with the image of a Phelddagrif not helping
Because of that, it's only logical to say that this dinosaur is probably not the best commander to build a deck around unless you want a deckbuilding challenge
Ghost-Spider dies to that, but you can flicker it into Gwen Stacy so it survives
If a Blightsteel Colossus is able to hit an opponent without being blocked, that player immediately loses the game
Number 248 Language English Legal Formats Commander, Legacy, Modern, Vintage Not Legal Formats Alchemy, Brawl, Competitive Brawl, Historic, Pauper, Pioneer, Standard, Timeless Rulings (10/15/2006) Anything that triggers during the resolution of this will wait to be put on the stack until everything is put onto the battlefield and resolution is complete
In the absence of any such decks in Limited, I think this is probably just garbage