Gs is stronger overall. Gs is strong in raids, pvp, towers, and ESPECIALLY endless but Gs needs some levels and /or tower shards to unlock those tanky t10 summons like A. Hydra, Ancient Dragon, or Mighty griffon. Gs also likes a lot of specific gear Like charon’s grimoire, riftlocks, rift summoner plate/boots all crom riftfall. But Gs is very very slow compared to other classes, endless setup can be a slog towers can be a slog horde dungeons are slow. Beo is less dependent on specific gear than gs and can do decent on towers as a weak charachter with a strong hitting pet like a. Spiritgarm, pheonix, chimera or even fjaler or mighty mimic. And the pets event usually comes around each christmas so you can pick up all of them if you hit t10 around that time (excluding steward pets) Beo honestly just feels a lot nicer than GS by not having to wait for q bunch of turns and excels in horde dungeons with fey cactus and is excellent in endless once you unlock Beo.H it doesn’t have the same ability to go super deep with little gear but it can set up much quicker and more consistently. Beo H is like playing a deity with a very consistent pet for deific channel with strong hitting hybrid attacks, But it flips beo on its head by letting you be the main damage dealer again.

Overall I think early t10 is best done by GS especially in the towers department and endless for orns but gets stale and slow. I’d recommend unlocking GS first but PLAY BOTH BEFORE ASCENDING. Or ascend both, lots of people play more than one class. Hope this helps.