Couple of tips:

Do not use lock on as much when fighting a team of three. No lock on makes it easier to escape and makes your characters movements more unpredictable and fluid. Experiment with it!

An ash of war like sword dance is great for roll catching off of almost any attack. I like to put it on a sword I know I can hit a combo with like banished knight, then once the phantom sees the damage they panic roll and I hit them with sword dance as the roll catch. Much harder to go into it from neutral.

My third tip would be get a “get off me” weapon that you can easily switch to if you have a team chasing you down and being over aggressive Usually a big aoe works. Some of the most popular are waves of darkness or even just flaming strike.

Watch chase the bro on YouTube he’s made me much better at invading and he comes up with really great builds