I use shield stance in a couple of scenarios. One is if I am turtling. Between bash, d2 AA, and toss, its very difficult to approach. The second main situation I go into shield is to straight up bully my opponent, doomsday style. If I have a health and meter lead, I will just go all in with shield bash, which does really good chip. d2 is borderline impossible to react to, d1 frame traps, b2 mixups, etc. Just go in and give them hell. The third main reason is that in specific matchups, it is just easier... for example green lantern. And finally... sometimes it just messes with your opponents head, because they are suddenly fighting a completely different character. Think about these things and make judgement calls on which stance to play in at any moment. This is probably the hardest thing about playing WoWo and we all need to work on it some, I am sure.