So Scott Pilgrim has two (three) timelines
Original timeline, which is what the comics are and Old Scott's future. And New timeline, which is what Scott Pilgrim Takes Off is. Oh, and there's also the movie but the follows the comics plot with a couple of changes for pacing reasons.
Scott will probably be composited, his movie version doesn't bring much to the table in terms of feats but the anime does. Old Scott shouldn't be used since Young Scott is the focus. Old Scott was able to take on the entirety of the Scott Pilgrim cast and win, including Todd (Though Todd has broken his vegan streak and had only eaten a single piece of broccoli to regain his powers, not sure if he was at full strength). Old Scott is the Ultimate Evil Ex, having learned all of Ramona's EXs powers and abilities, including becoming a vegan (Which makes him possibly comparable, but we don't know if all vegans are built the same, the future version of Robot #1 was stronger than Todd, so...). Scaling to the country level feat that Todd performed is a bit iffy, even if the rest of the cast was able to harm Older Scott.