Excalibur is pretty bad for combos anyway, it murders the rest of his combo damage, and it's not like he's already doing good damage in the first place. Only truly useful thing for the L version imo is picking up instant overhead.
M excalibur good for fast get-away movement or an easy way past careless zoning. can be followed up when he's sped up by x-factor, but I dropped Strider hard and didn't work at finding any good combos with it.