I think Oldtree's issue is that it mechanically disregards reflection, which should reflect all spells...I'd think this spell would rebound on the user, and then cancel reflection on yourself...Perhaps a better wording is:
Delays opponent's shield, does 1 damage per 5
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in your possession.
Basically, instead of going through the opponent's shield, it can shut it off for a turn, allowing creature penetration of enemy defenses, fitting
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's theme better.