I'd suggest looking into using a HTGR at least, but really, you'll need a bit more then what help I can give you if you're trying to power a end-game paradise engine by Reika and all you have now is a bit of bedrock dust, some basic machines, and a industrial coil(even if you used a High Strength Coil I doubt it'd be enough). You may even wish to ask Reika himself what he would suggest, but be warned, Reika appears to be a Dragon(if his Avatar is also his Fursona), and you know what they say about dragons.What could I use instead?
...They say plenty of things. Beware of Dragon is a good one. "Meddle not in the affairs of dragons, for you are crunchy and taste good with ketchup" is a personal favorite or mine.
*Yes I know that's not how Fursonas work, but it's a way of looking at them that amuses me to no end.