In finishing fifth, the Andy Stewart-owned grey produced his best performance over fences since winning a Grade One as a novice at Aintree
The Randox Health Grand National now beckons, but whether he will be schooled over Aintree-style fences has still to be decided.
"He's always been capable of being a decent horse, but things fell a little bit apart with his jumping," Nicholls told At The Races.
"Funnily enough, when he fell in the Hennessy it might have woke his ideas up because he's jumped well since that day, his concentration has improved and I think there's more to come from him.
"At Cheltenham he showed us he was coming back and that confidence booster at Kelso made a difference to him, that was good. The other day was a very good run and now he's going to Aintree with a chance.
"Sometimes we put a bit of spruce over our schooling fences - it's a funny thing because we made National fences at home for Double Thriller and when he got there he spooked at the first and landed upside down.
"Then again Neptune Collonges (who won the National) never saw one at home. With these good horses you've got to evaluate each one and have a look."