Ketras the Bull is a fun troop that shines with Divine Ishbaala. Without her, Ketras is fun, but a bit more of a liability than the time it takes to charge it without help (personal opinion). Needs a dedicated mana engine team to get the damage off before something decides to target Ketras.
Here’s a team you probably could build…
Alchemist (Rare troop)
Moneylender (Rare troop)
Ketras the Bull
Queen Grapplepot/ Goblin Rocket (Ultra Rare troop)
Lantern Banner (Shentang)
Fill Alchemist, use Alchemist. From there, Moneylender creates a ton of Red gems. Queen Grapplepot if you get some overflowed Yellow, otherwise Ketras the Bull will quick fill with those Red.
This assumes you have no traits on any troop, although the 2nd trait on Alchemist is highly encouraged.
Goblin Rocket (1st trait encouraged) also works for Queen Grapplepot if you want to play a I win slowly without giving the AI a turn kind of thing.