See Aeran Gideon.

We discussed a five-colour planeswalker. I'm not sure if it can be made splashy enough, if not I prefer Gideon or someone similar, but it seems worth trying because it would be awesome if it can.

How can a planeswalker really feel five colour?

Can "flying 6/6 creature" be a middle ability?

What ultimate is sufficiently splashy? Maybe with an Aer theme?

Warrghbl stuff has historically been very splashy (as it must be for being the hardest available casting cost of 5); but doesn't seem to have any unifying theme beyond that.

How to out-splashy Maelstrom Nexus Maelstrom Archangel Coalition Victory etc? Even the lower end of the scale, Cromat is pretty splashy.

But sure, ok, "[-2] put a 6/6 flying dragon" token into play is pretty powerful. For Aer feeling, the +1 could be something about mana fixing - but you no longer need really because you just cast in five colours. Perhaps something that steals some mana from an opponent somehow? ... Heck, if you want splashy; "[+1] Take control of target land"

Then - what for an ultimate? something like Conflux maybe? Flat out "win the game"?

What's the flavour of this walker, anyway?

Vitenka's musing on "how can you fix mana if you just cast in five colours" makes me immediately think

> [+1]: Add to your mana pool.

I'm not suggesting that we replace Gideon with WUBRG walker, just that such a walker might be one of our other two walkers.

Ah, sorry! That makes more sense.

I wonder if we could possibly do ultimate "win the game"? Amateur designs massively overuse that, but a planeswalker naturally comes with a mini-game of keeping it alive, rather than just cheating it into play. It would be a very very splashy ultimate, one of the shortest. OTOH, something powerful but not that bald would be more flavourful.

I wonder what the flavour could be. I doesn't fit any of the existing walkers I know about (unless a colourless one?) An idealistic planeswalker devoted to diversity? An uber-planeswalker? A planeswalker under the effect of some sort of mana effect?

Could it be a planeswalker version of any existing 5-colour card? I was thinking of Phelddagrif for "surprisingly flying" but I'd forgotten that was only three-colour.

I can't find where we discussed it, but at some point in the history of our history of Aer, I think we mentioned a planeswalker as being the one who set Aer up and created the mana stones that draw from the Gloaming. Perhaps this is an elvish Oldwalker who didn't die after the mending, and is now a "regular" planeswalker, albeit one who uses all five colors. Maybe this planeswalker is the leader of the Senate or an otherwise important figure on Aer and has been for centuries, keeping the Gloaming secret from the rest of Aeran society.
I love Alex's suggestion of a +1. It's simple, beautiful, and rather dramatic. I think all of the abilities should be similar. Wizards has said they may print another four-ability walker if it was appropriate: What if this was one? Five colors needs to feel powerful somehow, and that's a good way to do so. Perhaps he/she could have three very splashy +1 abilities that are simple yet powerful.

Possible abilities brainstorm:

• [+1]: Destroy/exile target permanent. _(Has been done by Karn, Bolas, and Vraska, though. It's sort of the go-to dramatic ability.)
• [+1]: Untap all creatures you control.
• [+1]: Draw some cards.
• [+1]: Look at the top several cards of your library and put them back in any order. (Too long? Too blue?)

I like those suggestions.

Further brainstorming:

• A viashino who channels a connection to the Ur-Dragon, tying together the Aer and five-colour
• Themed around fives: draw 5 cards, 5 damage, 5 tokens, etc
• 5/5 flying token, possibly as [+0]
• Cast a card from your hand without paying its mana cost, but it's similar to + Add WUGBR, and I prefer the mana ability.
• Search your library for a card of each colour
• Ultimate: as above, but cast them/put them OTB
• Target player sacrifices 2 permanents

Other thoughts, not about abilities:

• It's possible the whole set could be set back in time, if that helps -- eg. maybe gideon USED to be 3+ colours, but became mono-white
• Or tie into the timespiral story -- a pre-nerf planeswalker could have travelled forward in time temporarily, explaining the extra-splashy-ness (though we probably don't want to mess with that).
• Aside: This is ridiculous, but while I was thinking about time, I wonder if the mono colours could be flashbacks to famous mono-aligned planes or places in magic's history, eg. red from a red site in ice age, black from the black plane, etc.