Basically titel. I was on Explorer Niv to light and my Control opponent had only 1 life. I had bring to light and dovins veto in hand, while my opponent had only 1 card in hand. This was a guaranteed win, since I can bring to light for lighting helix and protect it with veto. But I had only 1 white mana available. No problem since helix is only a 2 mana card. But Arena forced me to spend the white mana on the converge even in full control. Luckily the last card of the opponent wasnt a counter so it didnt matter in the end. For the future I would like to know how to avoid this. Any tips?
This is the right answer - When you need to be very specific about what mana you spend, full control (or put a stop on the phase ladder) and then click the specific mana you want to pay