When Tree of Redemption’s activated ability resolves, your life total will become equal to the Tree’s total toughness (taking into account all effects that are currently modifying it). You will gain or lose an appropriate amount of life. Any effects that modify or trigger on life gain or life loss will do so here.
Simultaneously, Tree of Redemption’s toughness will be set to your life total, which will then be modified by any other effects, such as equipment or counters.
For example: Tree of Redemption is enchanted with Dead Weight (making it -2/11) and you have 7 life. When Tree of Redemption’s activated ability resolves, you will gain 4 life, putting you to 11, and the Tree’s toughness will be set to 7, making it -2/5 after we apply Dead Weight’s effect.
The exchange will only take place if Tree of Redemption is on the battlefield when the ability resolves, and only if you can gain or lose the appropriate amount of life. For example, the exchange can’t happen ever if you control Platinum Emperion.
Today’s Rules Tip was written by Charlotte Sable, a level 2 judge from Ontario, Canada.