What would be a good deck to switch to from what I have, and then what kind of deck should I aim for once I start upgrading?
Thanks in advance
Well RoL is not a bad start, but my advice would be to choose a rainbow God Killer and aim for that. It's the standard deck that most people use for FG grinding, and even though it takes a long time to upgrade, what it does for you is give you a solid base of upgraded cards in every single color, and some of the better cards to have upgraded in those colors. Once you have them, you can start branching out and building other decks with greater ease.
A few things to aim for because they are just so darn useful to have:
• Upgraded Shards of Gratitude (you can win the shards from T50)
• Supernovas (upgraded Novas)
• Other useful upgraded cards:
- Flying Weapon
- Ray of Light
- Ball Lightning
- Elite Otyugh
- Quanta-producing creatures in your favorite element (these are usually 1/1 that also produce quanta when upgraded)
I suggest reading the threads in the forum dedicated to deck building to get a better idea of what you're looking to achieve in terms of a deck. Expect to take at least a month building your first good upgraded deck though ... probably longer !