I've been told it can be really difficult.

nah, in one of the challenges with the right relic and i think on the medium difficult settings for more lasting enemies.  
 
Edit :
it´s the "Stay in the Air" Challenge. Just don´t stay 6 or 8 Seconds in the Air and they will respawn infinite. You could also try 10th Circle.
 
Relic is "Coin of Plutus" 

" nah, in one of the challenges with the right relic and i think on the medium difficult settings for more lasting enemies.   Edit :it´s the "Stay in the Air" Challenge. Just don´t stay 6 or 8 Seconds in the Air and they will respawn infinite. You could also try 10th Circle. Relic is "Coin of Plutus"  "

another good advice could be to use that holy cross magic, max it out in skills, then use it on infinite magic.
 !

It's 616!

" It's 616! "

There is a spot in the sand level where you have to push a giant cart to place between two gaps to get across. The enemies infinitely spawn on the ground that area until you move the cart. Switch the difficulty to Classic and use the relics that increase your combo hit count, protects you from knockdowns, and the one that sometimes deflects enemy attacks.
 
The trophy is very simple just like the rest of the game. I think that Ryan guy sucks really bad. This was my third Platinum.

triple six mafia mafia

I just got it, quite easy

" @eroticfishcake said:

" It's 616! "

No, it's 666. "

" @Alphiehyr said:

" @eroticfishcake said:

" It's 616! "

No, it's 666. "

The official devil's number is 616 im afraid... "

My friend done it and he says its really easy. He says when you get to the challenge where you have to maintain a combo the whole challenge, you should change the difficulty to the hardest one, then go from there. That way you don't end up finishing the challenge at a low combo number. I did the challenge on easy and the combo ended around 250. Oh and make sure you have a relic equipped that expands the combo window. So if you get hit the combo stills stays up.