This is based on my experience
In 10-20 Manas you can use Fire/Death decks it's quite powerful.
In 20-30 Manas you can use Water dekcs cause Magic damage ignore armor except some Monsters.
In 30+ Manas you can use Water decks too but you have to see what Rules and what your opponents often decks so you can counter it.
You can rent some cards that 0.1 DEC/Day that's quite powerful , don't rent something that you can't earn in 1 day / BEP (Break Even Point).
