mtg science commander deck Goonhammer Reviews The Fallout: Science! which lets you create extra token copies of creatures. MTG / Universes Beyond Fallout

Its mainly just a 2-drop that gives a lot of card advantage, but it can also be a key combo piece thanks to Boggart Harbinger setting it up

Negation should be a 4-of in most blue sideboards

Its not a perfect comparison with things like indestructible creatures and Callidus Assassin entering the battlefield tapped, but this is still a great tool for Dimir decks to have in their arsenal

Ramp and defense

I said it when talking about Queen Marchesa and Jared Carthalion, True Heir: you need to combine monarch with other strategies for it to work at its best

Defender vs Flying Unless it also has flying or reach, a creature with defender cannot block flying creatures