Thus deck is weird. Why even use Riryoku when you have Union Attack? Better to add a spell that adds consistency.
Also, "Twister may not work in all situations as it can only target face-up spell/trap cards"
This is not true. You can turn self chain to "On", and then use any normall spell and the game will ask you if you want to chain Twister. Just say "Yes" and you can now target the normal spell. You will "destroy" it, but Twister does not negate spells, so you will still get the spell effect.
It still doesn't matter, because union attack effect kicks in during the battle step AFTER you use riryoku.... Meaning that you will still get the same attack if you half one of your own monsters, so riryoku only works with union attack if you steal from an opponents monster.