Heavy Arbalest 
Artifact — Equipment
Equipped creature doesn't untap during its controller's untap step.
Equipped creature has "{T}: This creature deals 2 damage to any target."
Equip {4}
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Cards that do something similar expected a card that isn't here?
Reports become test cases the matcher is graded against before an update ships. Delvefall isn't a chatbot guessing, it compares the printed rules text of every card with plain math, and examples like yours decide which differences should count.
Cement Shoes 100%
$0.13#21449
"Equipped creature doesn't untap during its controller's untap step."
+1 more matching line
Viridian Longbow 96%
$2.09#4585
"Equipped creature has "{T}: This creature deals 1 damage to any target.""
+1 more matching line
Stitcher's Graft 88%
$0.16#21515
"Whenever equipped creature attacks, it doesn't untap during its controller's next untap step."
+1 more matching line
Hexplate Wallbreaker 85%
$7.69#3483
"Whenever equipped creature attacks, if it's the first combat phase of the turn, untap each attacking creature. After this phase, there is an additional combat phase."
Genji Glove 85%
$8.58#1233
"Whenever equipped creature attacks, if it's the first combat phase of the turn, untap it. After this phase, there is an additional combat phase."
+1 more matching line
S.H.I.E.L.D. Spy Kit 83%
$0.19#22396
"Whenever equipped creature attacks alone, untap it and scry 1."
Sword of Feast and Famine 82%
$38.74#539
"Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control."
+1 more matching line
Assault Suit 80%
$0.27#4132
"At the beginning of each opponent's upkeep, you may have that player gain control of equipped creature until end of turn. If you do, untap it."
+1 more matching line