The Doctor Who set introduced a partner-style mechanic where creatures with doctors companion can partner up with any of the doctor-type cards from the set to be your paired commanders
So, except for some overpriced cardsthere, I said it, hate me collectorsprices wouldnt be affected that much because demand would increase with supply
While merfolk doesnt go as wide as, say, elves, having a critical defensive measure against removal at any cost is great, especially if youre going to lose a creature anyway
Two-card death combos, at least for the purposes of Commander, fall into the same category
Winding Constrictor Creature that adds an additional counter whenever one or more counters would be placed on an artifact or creature you control, synergizing with The Ozoliths counter management