Welcome to the community!
Illusia definitely is challenging, with the sheer amount of special lands and warps that you seem to step on at the worst times.
I like to use a mostly-Neutral deck that is also anti-Neutral in this match. Armored Dragon, Saint and Banishing Ray work very well, as does Mothman (possibly with Phantasm to protect against Faustina's mass damage spells). Trade is very handy, and Telekinesis always works well against the AI (just move high-level creatures off their lands and snatch them for yourself!)
I also like to load up on spells that work well on the map itself, like Permission (cut your lap path in half), Manna and Spartoi (put Skeletons on random empty lands, which helps overcome the special land problem). Of course, including lots of Crusher and/or Poison Mind will help minimize things that are giving you trouble too.
Several of the cards I suggested have discard requirements, so you'll want to include plenty of extra card-drawing in your deck or you'll find yourself with an empty hand too often. Brass Idol is handy, and Metamorphose Belt works very well with it (since your enemy is sure to have a full hand, Grass Strider will consistently have high ST in battle).
You could also include the classic Goblin's Lair + Borgess + Red Cap strategy, which always gives the AI major problems.
Hope this helps!