Like, even if we didn't consider our scaling system for Pokemon, the lions don't stand a chance in this.
They can't kill Cleffa (Meteor crash feat.) nor Magikarp (Mountain jump, space jump, Team Plasma's lake bombing.), nor Rotom (Made of plasma.), Slugma, Geodude, Aron, Onyx, Steelix, Grimer, Gastly, probably not Cryogonal, nor Jellicent....
Also, if you arranged 1 billion lions in a square, like you would an army.... Well, a lion is like 1.8 to 2.1 meters plus a 1 meter tail. So assuming the lions are all the biggest they can be in all directions (Absurd as that is.) that's only like, 3.1 meters.
Square root of 1 billion is 31622.7766~. Times 3.1 = 98,030.607
Meaning a square-shaped gathering of 1 billion, even if you included their tail length, would be less than 100 kilometers on each side.
Meaning the lion army only takes up about 10,000 square kilometers. That's less than half the area of Wales!
Do you know how small Wales is?! Look!
& Africa, the natural habitat of lions? 30,370,000 km2. That's 3,037 times bigger than 10,000 square kilometers!
Meanwhile....
en.wikipedia.org
7.0–7.9 | Major | Causes damage to most buildings, some to partially or completely collapse or receive severe damage. Well-designed structures are likely to receive damage. Felt across great distances with major damage mostly limited to 250 km from epicenter. |
Even HALF the range of a Magnitude 7 or higher Earthquake (Like from Magnitude!) will have a greater diameter (If not excessively larger.) than the length of the lion group.
One Magnitude/Earthquake, & millions of lions are dead.
If it were ONE TRILLION lions, they might be SLIGHTLY challenging, but only because of sheer numbers; 1 trillion lions just barely fills a little less than the area of the United States of America.
....Except, not really because a third of that lion body length is their tails, lol.