The sure winning team that I used all the time would be you HAVE TO pick the Defender Role ( Green Robe Character ) and Alice. While Sam and Celeste are just for 2 eye candies. 😁
Alice has Passive Skill which lets you roll additional D4 damage dices in the beginning of every turn based on number of mana you have. For example if you have 4 mana ( blue dots ), then there will be 4 red dices rolling FOR FREE in the beginning of every turn.
As for Sam and Celeste, you have to pick Total Mana Upgrade that will increase your total mana to at least 5 dots. Only then Sam and Celeste Passive Skill will be activated.
Now let's talk about the upgrade. Upgrade that you should be targeting are D8, D4, Total Mana, Mana Regen and Ring Upgrades.
Between Total Mana and Mana Regen, the latter I personally think is the better one since you don't have to save any mana for your next attack.
Between D8, D4 and Ring Upgrade, always go for the Ring if you see it in the options because it upgrade all your dices regardless of colors.
Now for strategies. Pick your ultimate skill at every beginning of turn and just spam your own skill as much as how much mana you regen. For example, if you have 4 total mana and 3 mana regen, then use your own ultimate ( orange dot ) and spam your own skill next to it 3 times. Your skill rolls 3 colors of dices at once so you'll get damage, heal and shield at the same time. This is why you should always go for the Ring Upgrade, but if you don't see it anywhere then choose any upgrade in the options based on my recommendation above.
You don't have think about the flow or sequence between these upgrades. Just think about what you need most at the time and that is it for the strategies. Since you got Alice in your party, you'll get free 4 damage rolls every time. Don't worry about the small numbers in the beginning. Once you progress and get upgrades, you'll see your damage will go up to 200-250, heals 100-150 as well as shields 80-100.
Because you pick the Defender Role and Alice is in the party, you'll see Sam and Celeste Passive Skills doesn't really matter to be honest. So you can change them to whoever you like 😁