MH3 upgrades
Counterspell is mostly outclassed by Flare of Denial
No longer need 2 Ottawara with Sink into Stupor playing a dual role as land and disruptor
I'm not convinced Dismember is correct in a list with Sink and Flare, Flare is good enough early on to deal with things we want Dismember for, and Sink would help deal with later threats to close a game out, when the life total could be low. I think paying 7 life in one game makes it close to unwinnable so I'm risk averse on that for the maindeck
Everyone else is playing Vodalian Hexcatcher, and why wouldn't I want 12 lords? Just gotta be willing to play it later in a game as it's a bad attacker and it's sac ability doesn't seem like something you wanna activate more than once a game. I think I just miss Silvergill Adept lol and this is the slot
Harbinger of the Seas is probably the last threat you wanna play, the primary function is "creatures can't be blocked" not so much "opponent can't play Magic" In Modern decks and players are tuned and ready for Blood Moon, no reason Harbinger would catch anyone off guard. The decks that really care about their mana are building up to some pay off, there's no hurry to jam the Harbinger ahead of other cards, like Tish or Svyelun
I like this list a lot, I think the meta is full of decks that are hard to overcome, but this list is where Merfolk wants to be. The gameplan is relatively simple, curve out into a decent board state, use Flare and Force help protect the early game if you NEED to, and having 3 mana up later on is a very good place to be when our opponent's are playing around Tishana's, Flares, and flash bears while defending against a Svyelun
Sideboard is in disarray tbh, Hibernation is probably correct, not sure what the best answer is vs Energy decks