All you need is a single extra point of lifegain sometime before you end combat each turn
For example, if I target my own Phyrexian Missionary with Deadly Derision MTGA asks, Hey, dude, are you, like, totally sure you wanna do that!? Probably not a bad idea to leave this option On if you're new to MTGA (or playing while tired/bottle-feeding/otherwise distracted), but a lot of times what youre trying to do does make sense, so turn it off if you find Arena second-guessing you too much
Potential ways to track this include writing them down on paper or using dice, but any method that is clear and mutually agreeable is fine
Now an outcast monster bonder, Lukka must survive the wilds of Ikoria with the help of planeswaker Vivien Reid
One Piece TCG Deck Building Guide Not all colors value counters equally