mtg exalted commander deck Elite 5 Color Eldrazi - Ulalek, Fused Atrocity - EDH cEDH - 100 Card - Custom Deck Exalted Deck -MTG - YouTube

You can't sacrifice Koma itself to activate its last ability, but you can sacrifice any other Serpent you control, including Koma's Coil

I suppose theyll also be good in decks with bouncelands, like Boros Garrison

I personally like Tasha, the Witch Queen because it lets you play with your opponents cards, but Baba Lysaga, Night Witch works nicely for Halloween since it asks you to use your graveyard for value

Simic cards tend to reward players for taking basic game actions like playing lands, drawing cards, and casting spells, which makes it a powerhouse in pretty much any format, but especially Commander, which is all about ramp and card draw