Almost all effects commonly associated with water negatively affect your opponent's creatures, which is not a very fun keyword mechanic
While digitally-exclusive cards have come out here and there since the MicroProse PC game (and more so as of late in Magic: The Gathering - Arena ), the cards found in the game's Astral set do mostly live on through stills and other digital forms today, as well as the oversize promo card print run, the odds that these cards would ever see print as a whole remains a nigh-impossibility
Since it is a mana source, you can activate it in response to a spell or ability, like a tutor effect, pitch your hand and get the mana, get the next spell you want to cast, and then have the mana to cast it
Welder is more vulnerable but incredibly quick
I didn't have time to properly test out these matches as much as I'd have liked, but having played the Pokmon TCG competitively in the past, these new mechanics do appear to offer a good reworking of the game for mobile devices