What is the current oracle text of Obelisk of Power, and is it a triggered ability?

Ruling: Obelisk of Power is a triggered ability. The card text reads "at the beginning of each players first beginning step..." and there has been no errata to the English text. It triggers only during each player's first beginning phase of the game, not every turn.

Sequence:

• During your Beginning Phase (B), declare "Obelisk of Power trigger to channel one additional rune"
• Channel the rune(s) from Obelisk
• Then channel your normal runes for turn (C)
• Then take your draw

Nuances:

• The ability triggers while the battlefield is uncontrolled (does not need to be controlled to trigger)
• The turn player takes responsibility for adding uncontrolled battlefield abilities to the chain
• If you miss the trigger, your opponent gets to decide whether you get it retroactively or not according to tournament rules
• There are no mandatory triggers that happen automatically if forgotten