What made them especially good at the time was their status as Pendulum monsters, allowing them to take advantage of traps to negate or banish the opponents monsters, only to come back through Pendulum summoning the following turn
With these powerful abilities, they become a great support option for all manner of Spellcaster-focused decks
As for our Standard Thoughtseize, Devour Intellect, it's definitely not a Thoughtseize, but it still felt quite powerful
Both also have a nuke effect
Big splashy alternate wincons are definitely good for Commander
When properly Synchro Summoned, Trishula can banish one card from the opponent's field, one from their Graveyard, and one randomly from their hand