When Heimerdinger, Inventor copies tap abilities from multiple sources (like Vanguard Armory and Viktor Leader), can you activate multiple copied tap abilities at once, or do you choose one?

Ruling: Heimerdinger, Inventor copies all tap abilities from friendly legends, units, and gear, but you can only activate ONE copied tap ability per turn since activating a tap ability requires tapping Heimerdinger himself.

Sequence:

• Heimerdinger passively gains all tap abilities from all friendly legends, units, and gear you control
• To activate one of those copied tap abilities, you choose which specific ability to use
• You tap Heimerdinger (not the original source) and pay that ability's cost
• The chosen ability resolves
• You cannot activate another copied tap ability until Heimerdinger is readied

Nuances:

• Viktor, Leader does not have a tap ability (only a triggered ability), so there would be nothing to copy from him
• If you control multiple sources with tap abilities, Heimerdinger has all of them simultaneously, but can only use one per turn unless readied
• You tap Heimerdinger to pay the tap cost, not the original permanent with the ability