JL Big 7 vs Female 7

Meggan
Jean Grey(no phoenix, just the"telepath 2nd only to Xavier"version)
Sersi
Snowbird
Invisible Woman
Polaris
Elektra (foil for Batman)

vs

Superman
Martian Manhunter
Wonder Woman (standard equip)
Green Lantern
Aquaman
Flash
Batman

1 second prep so everyone can raise their shields and for Lorna to negate the gravity in the area or erect a repel field or whatever. (to avoid the speedblitz at the 1st millisecond problem)

Also Meggan can't turn into Phoenix or into something that can decimate the JL singlehanded. She can only turn into characters who are within their power range or weaker.

Snowbird.

Oh I forgot to include Snowbird. The rule for Meggan also applies to Snowbird. Snowbird can not turn into beings that are way more powerful their normal power range.

Snowbird can kill elder god level beings without transforming, as shown in Chaos War.