
TLDR: If you plan on playing Aequor, pull her. You'll want to get Miryam at some point to help with her Aliemus issues, but as long as you have at least 1 other Lemurian she'll be set for arc 2. Did you not read the description? Yes, go pull her. She makes Aequor not only competitive but thrive. She's busted as hell even at E0. She's the most affordable upgrade to the realm, and the only thing that holds her back is her reliance on an Aliemus battery (AKA Miryam) to let her actually Exalt. She does reduce Aequor's survivability, but that's a small price to pay for a significant damage increase. If you're a new player pull her, grab a free Corposant, try to get Miryam, and slot in Goliath and you'll autoclear the entire story once you've got enough levels on them.
For a long time Aequor was by far the weakest realm. Its damage sucked (tentacles did NOT scale well), its survivability was OK at best, and it was mainly carried by the utility of Miryam's Aliemus funnel. But no more, said BiaV! For the low low price of up to 90 pulls, you too can make tentacles actually do damage, have slightly worse survivability, but also add one of the strongest support characters to your team.
Meet Murphy: Fauxborn (GMurphy from now on, as per usual with alts). If you want to run Aequor, she's an immediate first choice now. Her mere existence on your team 1) increases the damage output of your tentacles, 2) provides a lot of passive buffs while in arc 2 when paired with another Lemurian (the more there are, the stronger the effect), and 3) deals a surprisingly high amount of damage herself. All of these things give Aequor a competitive edge again, which is GOOD but... I'm not very happy about having to specifically pull a character JUST to fix the weaknesses of an archetype. With that said, there are some drawbacks. You trade off the consistent shield spamming of the original Aequor realm for a one time big shield (which is probably enough honestly) every 3 turns. In addition, you can only enter red stance every 3 turns. Despite this, your tentacle DMG scaling off your team's max HP is a significant increase in their base DMG, allowing them to actually do meaningful damage in arc 2. As with most arc 2 supports, her doing high damage is an expected powercreep compared to the more utility heavy low damage supports of arc 1. At E0 she deals somewhere between Pickman (assuming he isn't stocked up with multiple Chromaphage) and Clementine (closer to Clem than Pickman). However, her E1, E2, and OE let her deal even more damage, easily surpassing both and practically becoming a sub DPS. Her Command Cards are also quite good; her 3 cost has a different effect depending on the stance; either a tentacle DMG up + adds 1 tentacle, bonus shield + next turn shield retain, or a mini nuke somewhat equivalent to Tulu's 4 cost. Her other card is laughably broken; a 0 cost draw 2 and +2 Arithmetica for a measly 5% self Sacrifice infliction. At E3 she can loop this, practically allowing you to go infinite (well, as infinite as arc 2 would let you).
Her Exalt is pretty interesting. It's both a shield, a 5 hit attack (multi hit matters for Raging Waves AKA red stance), and it applies a new debuff, Birth Ritual, that lets you stack Sacrifice on the enemy based on the damage your team does. Stacking Sacrifice is another one of her gimmicks. Her Rouse lets her apply it based on her damage, her signature wheel applies Birth Ritual stacks, and as I just mentioned her Exalt does too. With a strong enough time reaching obscene numbers on this is very possible, but for the average player who's reading this, you can expect a decent (rather than lethal) amount of extra damage from it.
Speaking of E0, let's talk dupes. E1 and E2 are damage upgrades to GMurphy herself. This isn't too important for a traditional support, but for GMurphy and the context of arc 2 this actually does matter. With that said, SHE DOESN'T NEED THEM TO BE USED. In fact, she might be one of the most powerful E0 characters I've tested in arc 2. While her damage output becomes noticeably better with dupes, you can easily clear most normal content without them. For utility, E3 lets you pull her Abyss Hymns card from anywhere after using her Strike/Defend, which means that at worse it's a draw 2 +1 Arithmetica, or if it started in your hand, it's a draw 4 +3 Arithmetica. This is obviously absurdly strong, but the extra self Sacrifice infliction might be risky. It's definitely most appreciated on a well built account. Her Overexalt is very strong, but GMurphy's lack of built in Aliemus gen makes it difficult to reach it. But wouldn't you know it, her best teammate Miryam happens to dump Aliemus to a single person easier than anyone! Without Miryam I'd avoid aiming for it, but if you do have her you can make GMuprhy do absurd damage.
I can safely say that GMurphy has (mostly) salvaged Aequor teams. I haven't tested every possible team comp yet, but she makes Tulu actually feel usable which is something I didn't think I could say in arc 2. Hell, she makes GOLIATH usable as a DPS! GOLIATH! She seems to be fine on any team as long as you have at least Miryam paired with her, but she's very clearly meant to work in pure Aequor or Aequor/Chaos combos.